T.R | Title | User | Personal Name | Date | Lines |
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317.2 | SOUNDS REASONABLE TO ME... | GHANI::CASEYA | THE DESERT RAT RC-AV8R | Wed Sep 23 1987 11:54 | 20 |
| Tom,
Should we (or is there a way to) move all glass related replies
here from topic 288??
I haven't tried the method you've described but I have heard of
it, though not in any detail. It do indeed sound like an easier
way to go...I may give 'er a shot on my next bird (if I ever get
off my dead A** and build one).
I just acquired a 75" Mark's Models Masterscale P-51B with Malcom
hood which I may get excited enough about to get busy in the shop.
Sometimes it's almost a curse to have one or more reliable birds going
(I have three) as you can get complacent and lose incentive to keep
building...but, when I do, I'll try yer' method, starting with the
tail-feathers to see how I like it. I'm quite satisfied with the
method I've been using but if yer's saves time/effort and still
produces the desired quality result, I'll switch in a heartbeat!
Adios, Al
|
317.3 | a fuse in ONE piece? | WRASSE::FRIEDRICHS | Jeff Friedrichs 381-1116 | Thu Sep 24 1987 16:19 | 11 |
| Hey Tom, would you mind on expanding on the sentence...
" A fuse can be done in one piece. "
Even with the tail section already completed, I can't imagine
using one piece for the whole fuse (unless I cut that 1 piece into
3 or 4 smaller pieces...)
Cheers,
jeff
|
317.4 | how to do it in one piece | SPKALI::THOMAS | | Fri Sep 25 1987 13:28 | 23 |
|
Jeff, I'm not sure if you have every covered with cloth but,
the fiberglass cloth that is used is extremely flexable. The
best way to cover a ship is to first cover the vertical and horizontal
stabs then cover the fuse when this is done and dry then install
the stabs into the fuse. The fuse can be covered is one piece of
finerglass by setting the fuse on a table turtle deck up. Drape
the cloth over the fuse. Using the clear epoxy paint or thinner
epoxy brush the adhesive over the covering. The adhesive will
penitrate the weave of the cloth and adhere the cloth to the balsa.
Procees with brushing the adhesive into the cloth and work your
way down one side of the fuse. When you reach the bottom corner
lay the fuse on it's side and continue the application of adhesive
to cloth until one half of the bottom is covered. At this point
you will trim off the excess. Now go back to the side that has
yet to be adhered to the balsa and repeat the brushing process.
When you get to the bottom overlap the cloth at the center seem.
Let it all dry and then add a second coat.
Ton
of the fuse start brushing the other side. When this is finished
|
317.5 | a question for the experts | LEDS::HUGHES | Dave Hughes (LEDS::HUGHES) NKS1-1/E3 291-7214 | Tue Jan 31 1989 09:13 | 18 |
|
I finally spent a few minutes working on the SS40-Bipe last nite.
I'm about ready to join the bottom wing halves. I love my palm
sander, I got the leading edges into shape in 10 minutes.
I've got a question for those of you who have built SS40s:
Are you supposed to put the fiberglass tape on the top and bottom
of the wing, or just the top? My plans don't say anywhere, but
seems to indicate the top only. The bottom of the wing has a 1/16"
ply sheet at the trailing edge to take the wing bolt. Is that
supposed to be recessed in, or sit on the surface (if on the
surface, then the glass will bump over the edges). I at least have
to flatten the center section a bit since the ply goes over the
dihedral. Is this similar to or different from other Sportster
designs?
Dave
|
317.6 | Glass both top and bottom center of wing | LEDS::ZAYAS | | Tue Jan 31 1989 13:39 | 6 |
|
Glass both the top and bottom with tape, Dave. After you get that
in, worry about the bottom fairings and protection for the bolts.
Please don't built it without the glass tape on both sides of the
wing!
|
317.7 | Both Sides like Fred Sez | LEDS::WATT | | Tue Jan 31 1989 22:26 | 12 |
| Dave,
If you plan to try Bill's full speed landing manuver so nicely
demonstrated at lunch today, I'd build that wing strong. Seriously,
the glass should be top and bottom with the bolt plate and fairings
going on afterward. I recessed the bolts through the fairings by
cutting holes with a brass tube. This makes nice clean cuts in
the soft balsa where as a drill will tear it. Lesson learned from
the SS20. I glassed my wings past the fuse sides and then faired
in the height difference with light filler and a large putty knife.
Do the bottom wing the same way you did your SS20 wing. By the
way, how does the gear go on on the bipe? Is it on the fuse like
the Aeromaster?
|
317.8 | Try this trick | LEDS::ZAYAS | | Wed Feb 01 1989 19:03 | 6 |
|
> the edge frays horribly
Yep, I've had that trouble too. I draw a thin line of CA where
I want to cut the glass tape and then cut along that line. Presto!
No more frayed edges.
|
317.9 | CA all the Way | LEDS::WATT | | Thu Feb 02 1989 08:37 | 14 |
| Dave,
I use Fred Z's method to prevent fraying. I use thick CA and
put down a very small amount and immediately follow by wiping it
with a paper towel. THen I cut down the middle of the line and
no fraying! Before doing this, I had all sorts of problems that
required lots of sanding to correct. I tried the CA attachment
method that Great Planes recommends on my Electrostreak. It worked
great and saved having to wait for epoxy to dry. It didn't take
much CA and it was easier than the Epoxy method I have used in the
past. The only problem is the vapors and you have that one licked
with your fans. I need some ventillation in my shop.
Charlie
|
317.10 | Please elaborate | LEDS::HUGHES | Dave Hughes (LEDS::HUGHES) NKS1-1/E3 291-7214 | Thu Feb 02 1989 10:47 | 8 |
| re: < Note 813.68 by LEDS::WATT >
-< CA all the Way >-
Please elaborate on the "CA attachment method" or point me to
the note that explains it. The instructions with the SS40-Bipe
recommend using polyester resin to attach the glass cloth.
Dave
|
317.11 | | SA1794::TENEROWICZT | | Thu Feb 02 1989 12:47 | 20 |
| When I fiberglass the center section of a wing it's somewhat different
that what you guy's have been talking about. To start I put a piecs
of masking tape onto the glass cloth. This stops the fraying. I
begin the glueing by attaching the cloth using CA to the entire
rear of the wing. Next I mix up some epoxy and spread a thin coat
on the bottom of the center joint. The cloth is wrapped over this
epoxy. The epoxy is then squeeged(sp) into the cloth and the excess
pushed towards the leading edge of the wing. I do this all the way
around the winguntil I reach the top. Usually a second mixing of
epoxy is needed to cover the top of the wing. Now I trim off the
cloth at the trailing edge that had been CAed. The epoxy on the
top is spread and the cloth (still one solid piece) is layed down
on the top. The squeege(sp) of the epoxy is done and all excess
is scraped off on the wing at the trailing edge. I then let the
epoxy cure and then trim and sand the trailing edge of the wing.
Tom
|
317.12 | Here's The CYA Method | LEDS::WATT | | Thu Feb 02 1989 13:25 | 22 |
| The CYA method is the same as Tom descirbes except you tack the
trailing edge and let it set, then pull the cloth dry over the wing
and around the bottom. THen spread THIN CA over the cloth, starting
with the center. It spreads out by itself and you just add enough
to saturate the cloth. The stuff makes a prolific amount of vapor,
much more than normal since you are spreading it out over a large
area. Don't breath it or let it get into your eyes. Continue the
CA treatment all around the wing, pulling the cloth tight as you
go. The great thing about this is you are done and ready to sand
as soon as you get around to the trailing edge. No waiting for
the epoxy to dry to do the other side. I did my last plane this
way and I like it better than epoxy. You don't even use very much
CA on a normal size job. Probably 1/4 oz or so. The last couple
of Great Planes kits I have built have suggested this method with
a slight variation. They have you spray a light coat of 3M contact
adhesive on first to hold the cloth in place. I found this unnecessary
and I didn't have any of that stuff handy. The final results were
better than I get with epoxy unless I do two coats which blows another
day waiting for it to cure.
Charlie
|
317.13 | polyester over CA? | LEDS::HUGHES | Dave Hughes (LEDS::HUGHES) NKS1-1/E3 291-7214 | Thu Feb 02 1989 13:55 | 4 |
|
I want to use polyester resin over the cloth to get a smooth
finish. Will that go on over the CA if I use CA to glue the
entire cloth down?
|
317.14 | | HEFTY::TENEROWICZT | | Thu Feb 02 1989 14:03 | 9 |
| Well Guy's I have a little clue for ya, I use 5 minute epoxy
for the job. Also if one uses a straight edge of wood for the
squeege you get a very smooth finish.
Tom
P.S. I'm glad someone could understand my description. I almost
couldn't after I wrote it.....
|
317.15 | fast hands | LEDS::HUGHES | Dave Hughes (LEDS::HUGHES) NKS1-1/E3 291-7214 | Thu Feb 02 1989 15:06 | 18 |
|
re: < Note 813.73 by HEFTY::TENEROWICZT >
> Well Guy's I have a little clue for ya, I use 5 minute epoxy
> for the job. Also if one uses a straight edge of wood for the
> squeege you get a very smooth finish.
Here we have the fastest hands in the east. I'm sure you can
do it that way, but if you take a moment too long, or the wife walks
in or the phone rings, you'll have a royal mess of epoxy glop! Once
that stuff STARTS to set up, you're dead!
I wish a good 30 minute epoxy was readily available, I know some
of the mail order houses have it, but Tower doesn't and I don't
order much from anybody else.
Dave
|
317.16 | Let's try again..however it's your choice | TARKIN::HARTWELL | Dave Hartwell | Thu Feb 02 1989 15:12 | 9 |
| Yep, and as Charlie said you can use CA only with no epoxy or resin.
When done simply use microballoons filler for a smooth and neat
surface over all of the CA'd glass and the small joint where the
glass ends on the wing. It makes for a nice lightweight strong
joint.
Dave
|
317.17 | Use polyester for the whole job | CURIE::ANKER | Anker Berg-Sonne | Thu Feb 02 1989 15:16 | 8 |
| Re:< Note 813.72 by LEDS::HUGHES "Dave Hughes (LEDS::HUGHES) NKS1-1/E3 291-7214" >
Dave,
If you are going to use polyester resin you may as well
use it to fill the glass cloth! That's what I always do.
Anker
|
317.18 | Me too, Me too ! | LEDS::COHEN | | Thu Feb 02 1989 15:35 | 22 |
|
RE .72,
Dave,
I use EXACTLY the same method as Charlie, when I'm done, I spread a real
thin coat of somehting like the white filler stuff (I forget its name,
model magic filler, or something like that) over the cloth and then
sand. You have to do it this way, since the dried CYA is REAL hard to
sand, and you don't want to wear away the cloth, anyway. Use a piece of
wax paper, or saranwrap (my new favorite) to smooth the cloth down as
you apply the CYA, this way you insure good balsa-to-cloth contact.
On the subject of SaranWrap, I'm building my newest plane using this,
instead of wax paper, to cover my plans. You can see through it much
better (although transparancy was never really a problem), but the big
win is in separating the glued components from the SaranWrap. It works
much better than wax paper, as it never shreds or tears like wax paper
can. Anyone else ever used it ?
Randy (Trapped in H*LL, thanks a lot, (8^D) )
|
317.19 | Tower has 30 minute epoxy... | TALLIS::FISHER | Only 40 Days till Phoenix! | Thu Feb 02 1989 16:19 | 17 |
| > I wish a good 30 minute epoxy was readily available, I know some
> of the mail order houses have it, but Tower doesn't and I don't
> order much from anybody else.
Dave - I just place an order this week from Tower and I said I wanted slow
epoxy and couldn't find the part number - no problem she ordered some
Loctite brand for me - 30 minute 2 part epoxy. I expect it any day now.
Just cause it ain't in the catalogue doesn't mean they don't have it!
Bye --+--
Kay R. Fisher |
---------------O---------------
================================================================================
|
317.20 | I only use CA on inner structures. | LEDS::LEWIS | | Thu Feb 02 1989 17:05 | 27 |
|
Dave, I don't know if it was stressed enough - I'm pretty sure
polyester WILL NOT cure over CA. Make sure you check the
compatibility beforehand. Also - I avoid using CA on any surfaces
I will have to sand _or_ paint, because of all the adhesives
(epoxy, ambroid, polyester, etc) I think CA is the toughest to sand.
To each his own, eh?
- Another tip -
I used heavy cloth last time I glassed a center section (seems like
about 20 years ago). I was worried about having a "step" where the
edge of the cloth was, and having to fill and feather out to hide it.
So I first sanded the area where the cloth would be laying. Just a
little, about the thickness of the cloth itself. In fact, I think
it's best to have the cloth slightly below the balsa surface so you
can have a little filler on top of the glass. The filler sands at
about the same rate as the balsa and the sanding job was very simple.
I liked using polyester resin to glass the center section, I used less
hardener than usual to give a little extra time. But the job was
done in no time. Can't afford that phone call at the wrong moment
though!
How come it seems that every time I write a reply I realize it's in
the wrong topic when I'm done? Oh well, you guys are doing it too.
Bill
|
317.21 | | SA1794::TENEROWICZT | | Fri Feb 03 1989 08:40 | 22 |
| Dave,
You should try some epoxy from Tom's in Chelmsford. It's
called Northeast Hobby Products. Great stuff. I've used just about
every brand of epoxy on the market and still go back to this brand.
if time is a problem you can do the application in two steps. The
bottom first and then the top. Use two pieces of cloth and just
overlay the leading edge. Once you do it a couple of times it's
really easy.
I used to have a buddy in NH who swore that the 30 minute epoxy
soaked into the wood better than the five minute stuff. What I've
found is that this is not the case. The Viscosity of the epoxy
determines how it soaks into the wood not the working time.
I don't like using the CA method because of the fumes and the
filling coat needed. For me the epoxy method is a one step application.
If feathered correctly no ridge is evident. A slight sanding and
your all set for covering.
Tom
|
317.22 | good advice here! | LEDS::HUGHES | Dave Hughes (LEDS::HUGHES) NKS1-1/E3 291-7214 | Fri Feb 03 1989 10:29 | 21 |
|
Gee, we have a mini-topic within a topic. It's related to
Super Sportsters because I asked a question about building
my SS, but it's turned out to be general interest.
I think I'll start a new base note about application of
glass cloth to wings, and put in pointers to the last few
replies. Some good stuff here.
After all this advice, I think I'm going to do what the
plans recommend - polyester resin. I'm not too concerned
about weight, and it's easy to apply and sand.
Bill's idea about recessing the glass cloth is a good one,
except in this case it's being applied over 1/16 sheeting
so there's not much room to indent without sanding right
through it. I may try it just a bit, though.
Thanks for the good ideas!
Dave
|
317.25 | | SA1794::TENEROWICZT | | Fri Feb 03 1989 10:52 | 19 |
| Dave, The idea you talked of about spraying the cloth with a
contact cement type adhesive and then adhereing the cloth to
the wing with CA (or epoxy,resin) sounds funny to me. I say
that demonstrated on a Satillite City tape a few years back and
wondered about it. Aren't you really incasing the contact cement
inside the glue joint your prodicing with the CA? Is this
as secure as without. Or does it really matter?
One of the guys I knew in CXO back in 85 didn't fiberglass his
center sections on his gliders. Rather he glued carbon fibers
across the joint in a few locations and then just glassed the
entire wing with .06 oz. cloth. Randy Renolds was the guy. He
was known for his Zoommmmmmmmmmmmmmmmm launches. Makes you think?
Myself, I'd still rather fiberglass.
About the way I do it as you squeege the epoxy and it flows out
of the sides I get a fillet of epoxy that smooths out the transition
from the wood sheeting to the glass cloth. very little sanding
or filling is ever required.
Tom
|
317.26 | Thinned epoxy | WRASSE::FRIEDRICHS | Where's the snow?? | Fri Feb 03 1989 11:52 | 9 |
| Don't forget, you can thin epoxy with 91% rubbing alcohol. Just
a few drops after you make the primary mixture. Thinned epoxy soaks
into glass and wood better and I believe it is just as strong when
it cures....sure is just as tough to sand!!
This was the method I used before I found polyester resin.
cheers,
jeff
|
317.27 | Locktite | TONTO::SCHRADER | Buddy can you Paradigm? | Fri Feb 03 1989 12:53 | 11 |
| I've been using some of the Locktite Epoxy Finishing Resin. This is
a two part epoxy of some sort that you mix similaryly to regular epoxy
(50/50 resin - hardener). It's much thinner than regular epoxy and
squeejes (sp?) into the cloth nice and easy. It also seems to get
pretty hard. The biggest thing that I like about this over polyester is
that there is no where near as much oder.
!
--+--
G. Schrader o___<0>___o CSS::SCHRADER
* * *
|
317.28 | Loctite is great stuff | USRCV1::BLUMJ | | Fri Feb 03 1989 16:32 | 8 |
| I concur with .3, the Loctite resin is great stuff. A bit expensive,
but definitely worth it. It is much easier to apply than polyester
resin and I believe it is stronger. Try it - you'll like it!
Regards,
Jim
|
317.29 | PIC products are very good | GIDDAY::CHADD | Go Fast; Turn Left | Sun Feb 05 1989 17:22 | 8 |
| I have used the PIC Laminating Epoxy and that is also good. The PIC Glass is
very good, tight structure and smooth finish.
Remember there is no strength in the resin, it is all in the glass/carbon
etc.. The resin bonds the cloth to the surface but adds weight, so the less
resin used the better.
John.
|
317.23 | No Polyester over CA | LEDS::WATT | | Mon Feb 06 1989 08:45 | 16 |
| I'm gonna continue the discussion even though it belongs elsewhere.
Dave, I don't use Polyester because it doesn't like CA, Epoxy or
almost anything. It does sand easier than CA or Epoxy but if you
do the CA or Epoxy properly, you don't need to sand it much at all.
If you don't want to use CA, I would recommend Envirotex epoxy which
is available at Summerville Lumber. You can thin it a little to
lower the viscocity and let it flow. You get a very smooth result.
My only gripe is the time it takes to set and the requirement for
a second coat to really get it smooth. THat's what I have used
on most of my planes. I have only used the CYA method once with
good results. I spent 10 minutes applying it, 10 minutes with my
eyes watering, 5 minutes sanding it, 10 minutes filling it with
microfill and I was done. It's as smooth as any of my epoxy jobs.
Charlie
|
317.24 | done! | LEDS::HUGHES | Dave Hughes (LEDS::HUGHES) NKS1-1/E3 291-7214 | Mon Feb 06 1989 09:06 | 23 |
|
Well, I decided to use the polyester resin approach. I had it
on hand, and it's easy to mix and use. It's thin enough to soak
into the wood a bit and soak through the cloth easily. I applied
a coat to the bare wood, then applied the cloth, rubbed it on with
a piece of waxed paper, and applied another coat of resin over it
to fill in the weave and leave a smooth surface. It sands easily.
I used the full 6" width of the cloth instead of cutting it to 4"
as the instructions said. By the way,I used the method of running
a bead of hot CA along the cut line to avoid fraying when cutting
the cloth - works like a champ!
I glassed the top and bottom surface of both wings, although
it was not called for on the top wing.
I applied a layer of Goldberg Model Magic filler over it to blend
in the edges and fill any small irregularities. (I just decided
to start another note about wood fillers, so don't tell me your
favorite filler here, go there.) I haven't sanded that yet, we'll
see how it comes out.
Dave Hughes
|
317.30 | K&B Polyester - curing time / sanding | GALVIA::ECULLEN | It will never fly, Wright ! | Thu Apr 12 1990 07:01 | 29 |
| I have a few questions on the K&B polyester covering epoxy. I have read Al's
procedure on using the materials and I know that later in this topic that a
question of the number of drops that should be put in the resin came up. SOooo -
I mixed my first couple of ounces out and added 8 drops per ounce. I found that
it was a bit tacky even a couple of days after putting on the glass cloth (K&B
.6oz). Last night I ventured to completing the top of the wing - I decided to go
above the 8-10 drops per ounce average and put in about 14 drops. I had no
problems in getting all the work done before the resin started to go off. A
couple of hours later it was dry to touch. This morning I took a bit of
sandpaper to it to feather the edges. It is still rubbery - I was using about
150 grade sandpaper - I know that it was suggested that the high quality Alum
Oxide paper be used but I have found it difficult to get it. Anyway as I try to
sand the edges down the resin becomes tacky and the sandpaper startes loading up
and I get some horrible black marks (from the, guess what, black colored
sandpaper) on the glass surface. Am I starting to sand too soon (7-9+ hours) ?
Does the resin need a lot more of the hardner than specified ? And does it sand
as easily when completly dry with the extra hardner added ?
I know that after putting the glass down and taking off the excess resin via the
roll of paper I should put another coat of resin on but I am afraid I need some
support here ! I don't want a layer of sticky resin to cope with.
Apart from this stick situation - the general covering is great. I can see it in
its final glory. Al, what do 'ye think ?
Eric();
|
317.31 | You might need a warmer spot | LEDS::WATT | | Thu Apr 12 1990 09:40 | 15 |
| Eric,
I've had the same damn problem with polyester. I think the main
problem with my efforts has been temperature. (Too low) My shop is in
my basement and I keep it about 65 degrees year round. This is not
warm enough for proper quick cure of polyester. I have switched to
using Epoxy and I'm much happier with the results. For either one, I
would recommend some sort of heat source if your shop is not above 70
degrees f. You might try putting your wing in a warm spot for a day
and see if it sets up. It should not badly load the paper if it's
ready to sand. It is not unusual to have a waxy coating on the surface
of polyester. It is in the resin to keep the air off, I believe while
it is curing. You can remove it with Eric's famous Resin Wacker.
Charlie
|
317.32 | you have a point there. | GALVIA::ECULLEN | It will never fly, Wright ! | Thu Apr 12 1990 10:27 | 16 |
| Charlie,
If it needs a warm environment to cure that may just be it as I think
the temperature is not nearly warm enough. I thought of putting it near
a heat source but recalled how some fiberglass cowls I made became
soft. I will try putting the fuse & wings in a warm room and see how
things improve over a day or so.
I will be glad to get a surface that I can sand easily - with little or
no loading of the sandpaper - since the surface I had before the glass
was good and I am expecting a super finish with the K&B epoxy - and
won't stop till I get it.
Thanks,
Eric();
|
317.33 | Hot Air and Old Catylist | 8713::TAVARES | Stay Low, Keep Moving | Thu Apr 12 1990 11:31 | 21 |
| Check first to see if you were using finishing resin, or
laminating resin. If its laminating resin, you are getting the
right thing since its made to remain tacky so you can do
additional lay-up.
If its finishing resin, then the soft surface could be the
aforementioned wax...it needs to be cleaned off as described. If
that doesn't fix it, your problem is either old catalyst or not
enough heat.
For heat, I generally put my spotlight that's above my bench
up to high and blast the surface for a few hours to get it to
harden. The surface temperature should be above 70 degrees. In
the summer, I'll just leave it outside for a while and that will
get it. Smaller parts are left on top the water heater
overnight.
Actually, 14 drops/ounce sounds suspicious to me; I think you may
have a problem with the catalyst. The 8 drops that is specified
should be more than enough. I've kicked off several ounces under
ideal conditions with just a couple of drops.
|
317.34 | POLYESTER _CAN_ BE FUSSY.... | PNO::CASEYA | THE DESERT RAT (I-RC-AV8) | Thu Apr 12 1990 11:52 | 81 |
| Re: .361, Eric,
I _ALWAYS_ over catalyze polyester resin if only because I'd rather
have it 'go off' tooo soon than not at all. If anything, this makes it
easier to sand simply because it's harder/more fully cured. I too had
some cureing problems when doing the MiG-3 repair/restoration last
December/January and I tend to agree with Charlie that the primary
contributor to my problem was the temperature, even though I kept the
shop warm while I was in it. I'm not sure that humidity might also
play a part. I believe that polyester works best the warmer/dryer the
outside air, understanding that this may be a disadvantage to some of
us at certain times of the year. However, Gene Barton sent me some
polyester he uses when I was having my problem; it is, per Gene, a high
quality boat resin and his only admonition was to shake/stir it well
before mixing due to a high wax content. Since K&B has no such
instruction on their container, I'm led to believe one of two things:
1.) that it contains considerably less wax...or 2.) that it _should_
be shaken/stirred well before mixing. Both could very likely be the
case so I suggest you shake/stir the resin well before measuring it
into your mixing cup then catalyze it at least 12-drops of catalyst per
ounce. Hopefully, this will cause a full, hard cure and solve half of
yer' problem.
The other half of the scenario, i.e. sandability, has _ONLY_ one cure
and that's the sandpaper itself! Aluminum (aluminium to you UK'ers) or
silicon oxide paper, preferably the former, is the ONLY sandpaper that
will produce the desired results without the loading problem. I
patently guarantee that you'll experience that gummy, loading behavior
with any other type of paper. The job _can_ be done with other than
the recommended paper but the aggration level, not to mention quantity
of sanpaper used, _WILL_ be quite high.
As Charlie mentions, many modelers feel that epoxy resins minimize
these frustrations at the cost of much longer cure times but yer'
committed at this time and must (or at least _should_) finish up with
polyester. If the prospect of grinding off a second coat is daunting
to you, try the recommendations above and make up a test panel of some
sort, applying glass cloth just as you did on the model, following it
with a second coat, then prove to yer'self whether it's gonna work for
you or not. I should mention that the hard, smooth, shiny second coat
will probably laugh at 150-grit paper; you'll want to start with at
least 80, yes 80-grit...just be gentle in areas of thin coverage and
work progressively down to the finer grades bearing in mind the fact
that yer' objective is to remove ALL the resin you can without cutting
into the cloth itself. Excessive weight from a glass/resin finish is
_*ALWAYS*_ the result of too little sanding...this is why I so strongly
recommend you make whatever effort is required to obtain some aluminum
oxide sandpaper. BTW, though this paper is more expensive, it's really
cheaper in the long run as a piece of it lasts virtually indefinitely!
Should you still be apprehensive about using a second coat of resin, go
straight to the K&B epoxy primer. Brush on a fairly heavy first coat
and SAND IT ALL OFF! Then spray on the second and, if required, third
coats, again sanding it all off except for the little that fills the
grain and other depressions...when down to the ptoper level of sanding,
there should only be a thin, milky-white patina of the primer
remaining. On the final [sprayed] coat of primer, I spray on a light
coat and sand gently son the airframe is mostly white but the
structure, grain, joints, etc. _can_ be seen through the translucent
coating. From here, yer' ready to apply color. Oh, BTW, I've never
had any curing problems with either the (K&B) primer or paint. The
primer dries quickly and the job goes LOTS faster than it may sound.
Sanding the primer may be done dry with alum-oxide ow wet with
wet-or-dry as you prefer (I like to wet sand at this stage) but be
aware that you must dry the surface frequently to keep track of where
you are. A big plus to wet sanding is that it keeps the [sanding] dust
down...on the minus side, you'll go through lots of paper towels or
whatever wiping off the sanding residue and drying the surface. I
still prefer wet sanding but, if you prefer to dry sand it, well and
good but you should _still_ finish up with a wet sanding with fine
(600) wet-or-dry to remove the sanding marks as much as possible.
Best of luck and be sure to keep us posted as to yer' progress.
I had _NO_ problem whatever
with this resin
__
| | / |\
\|/ |______|__(o/--/ | \
| | 00 <| ~~~ ____ 04 ---- | --------------------
|_|_| (O>o |\)____/___|\_____|_/ Adios amigos, Al
| \__(O_\_ | |___/ o (The Desert Rat)
|
317.35 | ONE MORE THING..... | PNO::CASEYA | THE DESERT RAT (I-RC-AV8) | Thu Apr 12 1990 12:51 | 21 |
| Re: last several,
I forgot to mention that I don't worry about whatever wax might be on
the surface of the resin after curing as it vanishes after the first
coupla' stroke of the sandpaper. I believe the K&B polyester yer'
using has quite a low wax content anyway to accomodate additional coats
and function as both a surfacing _and_ a finishing resin. In any
event, it's not necessary to locate/obtain any exotic chemical type
remover since, as I've said, whatever wax residue as might be left
behind is quickly dealt with by the sanding operation. However, it
_IS_ important that you sand between each coat, even a light, careful
sanding after application of the glass cloth helps ensure that the
second coat will adhere well. Allow me to add here that the difference
between a really good and a mediocre finish is SANDPAPER and the number
of hours you employ this most important of all finishing tools.
__
| | / |\
\|/ |______|__(o/--/ | \
| | 00 <| ~~~ ____ 04 ---- | --------------------
|_|_| (O>o |\)____/___|\_____|_/ Adios amigos, Al
| \__(O_\_ | |___/ o (The Desert Rat)
|
317.36 | Heat does it ! | GALVIA::ECULLEN | It will never fly, Wright ! | Fri Apr 13 1990 07:32 | 19 |
|
Well I went out and got a small heater to warm up the hobby room.
I decided to go for it and pour on the final coat of polyester resin
onto the fuse and wing. After doing this I put the whole lot into the
heated room, watching it every now and then. A couple of hours later
the resin was hard enough to start sanding - what a relief. Also
invested in some 60 grade sandpaper (I managed to get Alum Oxide).
So I am back on track to getting that superb finish.
'ye have to be really careful with that grade 60 !! And as stated
before it is very hard to see the cloth during the sanding - but we
are being careful !
Now its down to lots of sanding & patience.
Thanks for those replies, guys. You saved my day.
Eric();
|
317.37 | >Practice makes Perfect? | LEDS::WATT | | Fri Apr 13 1990 08:49 | 12 |
| Al mentioned one important thing that we all usually fail to do: A
test panel! If you're like me, you always screw up the first time you
do anything. (At least it doesn't come out as well as after you have
practice.) A test panel can save lots of grief since you can toss it
if you don't get the desired results. Keep trying until you do and the
results will be A-1 on your carefully constructed and sanded model. I
can't say that I've always followed this advice myself, but I do think
it makes good sense! All of these finishing techniques require
refinement and skill only acquired by practice.
Charlie
|
317.38 | Glass covering results superb !!!!! | GALVIA::ECULLEN | It will never fly, Wright ! | Tue May 22 1990 10:50 | 57 |
| Hi Guys,
Just a short bit on my fiberglass experiences lately...
I completed an ACRO WOT there a while ago and decided to go for the
fiberglass finish. This was my first real attempt at the fiberglass - I
sort of have my ACROMASTER half covered but have put in on the shelf
for a while. The instructions with the ACRO WOT suggested that one
leave the tail feathers off till the fuse is glassed if this is the
chosen method. This was good advice as it makes those curves easier to
sand and getting the correct shape easier as well - especially with
that heavy duty sandpaper. I picked up some of the Alum. Oxide paper,
80 grit I think, and as you said Al ye' need it. Anyway I covered the
fuse in two pieces or cloth. The first coat or resin went on (and most
came off with the toilet roll) to attach the fiberglass. By the way I
am using K&B products - .6oz cloth etc. The second coat went on and all
was beginning to take shape. After a lot of sanding, reducing to 1200
grit wet sanded, I had a lovely shiny glass surface. During the sanding
I managed to cut through the fiber in one place but that was easily
(read lots of work) patched. I am impressed with the finish - what more
could one ask for (Hhhhmmmm). Anyway the remainder of the plane's surfaces were
tissue & doped. Finally I put the tail feathers on and primed it all.
After _more_ sanding the overall finish was looking fantastic. I am now
ready for the painting. But I think that all in all, despite the smells
of the resin and all the dust (when dry sanding) it's a very satisfying
finish. Beats the hell out of any other finish I have seen. I might
even go that way from now on with any other planes I build.
I went out and got a nice small compressor as the one I borrowed had no
tank on it and although it was satisfactory - it was on all the time
and made a racket (read _negative_ neighbor points). Whatever about
wife points lowering with the dust - the neighbors being a bit close
would object eventually or even sooner. Which reminds me that its time
for a bar-b-q, yes we do indulge in this pleasant pasttime in good old
Ireland. Anyway, the compressor has a tank, cut-off switch, regulator
and all the usual jazz - the shop included some fitting and plumbers
tape at no extra charge. So I can spray away most of the time in piece
and quiet except when the pressure drops, when it comes on for a while.
I will probably be spraying everything in sight !!!! The output can be
regulated anywhere from 0-100+ psi. Before borrowing the other pump it
was a case of back and forth to the garage, well a selection of garages
around town, to get the spare car tire filled with air. As you can well
image it was a pain in the neck having to get up and replentish the air
in the tube, especially in the middle of a session. Gladly I can say no
more. So I am looking forward to painting in the next few days/weeks.
You may recall that I had a problem with the drying of the K&B resin -
I did until Al and a few others suggested that I had the incorrect
temperature in the area where the parts were curing. Well the blow
heater that I got heats up the room to a good temperature and all dries
out in the expected couple of hours. Generally temperatures on this
part of the globe will be a good bit down on the US average, the
opposite if you are in Alaska I guess !
Eric();
|
317.39 | Recent glassing with epoxy? | VMSSG::FRIEDRICHS | I'd rather be flying! | Wed Jun 08 1994 11:05 | 22 |
| Well, I am actually on the road to finishing my first real model in a
long time... (Sorry, I don't consider building gremlins in this
category... :-)
Anyways, it is an 80" Junkers CL-I; a WW1 (what else?) fighter. It is
stand way off scale, all wood fuse, foam core wings sheeted with
balsa... Time to think more about the covering..
I am going to use Parson's fiberglass... (Anyone have the number
handy?) But I am trying to decide how I am going to attach it...
Tom T talks about using epoxy paint... What he doesn't talk about is
using colors; he only mentions using clear. I am wondering if anyone
has tried using a color to attach the glass, then just shot a clear
coat over the top of it... No primer; the weave can show.. How did
it work out?? How did the seams come out??
I guess I need to do some test pieces as well..
Thanks,
jeff
|
317.40 | | WRKSYS::REITH | Jim WRKSYS::Reith MLO1-2/c37 223-2021 | Wed Jun 08 1994 11:09 | 9 |
| I used the paint method and it worked real well. If weave isn't a
problem, then I'd say it would be the perfect method. Filling the weave
is where the weight is.
One word of warning... Since the paint dries slowly, make sure you iron
out any wrinkles. They have enough "spring" to lift. The seams
disappeared!
Jim
|
317.42 | Alternative Method | 34873::SPOHR | | Thu Jun 09 1994 16:57 | 15 |
| Save yourself the time and effort required to paint.
Use 21st Century Fabric, it is a pre-painted fabric. Unbelieveable
results can be had with no more effort that ironing it on (follow their
recommendations on package) just like any other film.
I was preparing to go the glass and paint method on my new 1/3 scale
extra. But when I checked out a plane covered with this stuff I was
totally amazed. I swore that the plane had been glassed and painted.
These results were achieved by a guy who is an average quality builder.
Check it out... could save you time, effort, and cash.
Chris
|
317.43 | | 34873::BEATTY | | Thu Jun 09 1994 17:46 | 5 |
| Just remember that the iron on fabrics add nearly no stiffness to the
wing. They are insufficient for some open frame construction.
Will
|
317.44 | I don't like it | MKOTS3::MARRONE | | Fri Jun 10 1994 13:19 | 11 |
| I don't wan't to bash a manufacturer, BUT... I used the 21st Century
painted fabric last year, and found it to be the worst covering I ever
used. It wrinkles while you're looking at it! I'll never use it
again.
Its also VERY heavy stuff and thick enough that it shows seams
prominently.
Let the controversey begin!
-Joe
|
317.45 | Weight is my Enemy | LEDS::WATT | | Mon Jun 13 1994 09:41 | 10 |
| I don't like the epoxy paint method of glassing. I use Envirotex epoxy
thinned with alcohol following Dan Parson's instructions that come with
his glass cloth. I'm a plastic film guy because I hate the extra
effort and weight of a paint job. I don't care what you do, it will be
heavier if you glass and paint. I do like the resulting finish and the
ding resistance you get with glass, but remember - light planes fly
best!
Charlie
|
317.46 | | ANGLIN::SPOHR | | Thu Jun 16 1994 18:45 | 17 |
| Re.44
So far we are having good look with it here in the Midwest. The only
wrinkles I have seen were when I applied it. Those go away when you
heat it and rub it down with a mitt or cotton balls. None came back
to haunt me. The other guys whose planes are covered with it aren't
having any trouble with wrinkles either.
True, it is a bit heavier than film, but most iron-on fabric is as far
as I can tell. But, I can say it is lighter than glassing and then
painting; plus it is a heck of a lot less work and expense.
Anyway, no real contraversy, nothing works the same for everyone...
Some of us just know how to apply it better than others! ;-)
Cheers,
|
317.47 | | CSTEAM::HENDERSON | Competition is Fun: Dtn 297-6180, MRO4 | Fri Jun 17 1994 08:48 | 1 |
| Controversy!
|
317.48 | | UNYEM::BLUMJ | | Fri Jun 17 1994 11:25 | 28 |
| I spent a good part of the winter experimenting with alternative
finishing methods(to film).
I tried waterbased urethane, acrylic, and various enamels, lacquers,
and epoxy based paints. Although I did achieve some spectacular
results with urethane applied over light fiberglass/epoxy, the time
and effort was much greater than with film and was heavier.
I have had the opportunity to see some *VERY* high quality German
gliders that have film covered wings. They are totally acceptable
in every respect.
The secret to great film covering is surface prep and knowledge of
how to apply the stuff. I always inquire when I see a great covering
job and can say that I have seen spectacular results with Monokote,
Oracover and Ultracote over sheeted surfaces.
I have an article in a German magazine showing/explaining how to use
Oracover with a chemical adhesive activator instead of an iron over
sheeted surfaces. The end results shown in the pictures are great.
Too bad Hartmut/Bernd aren't around to translate.
I also recommend the use of light colors(white) on the top wing
surface with stripes/trim for visibility. White seems to handle
the heat from sunlight the best.
I still hate film, but it is by far the cheapest and easiest method
I have tried. If done well the results are very acceptable.
|
317.49 | Film is low drag | MKOTS3::MARRONE | | Fri Jun 17 1994 14:05 | 16 |
| I read an article recently about a test done to determine the lowest
drag type of covering for an airfoil. I think the work was done by
NASA. A single airfoil was tested in three conditions: bare metal,
painted, and covered with plastic film. It didn't give the make of the
film, but somehow I got the impression it might have been Monokote or
similar. At any rate, the results were not intuitive. It turned out
the film covered airfoil had the lowest drag, followed by bare metal,
with paint bringing up the rear.
So, Paint = Heavy + More Drag
Yuk!!!
Makes me think twice about glassing and painting my Mustang.
-Joe
|
317.50 | A little Here, a Little There | LEDS::WATT | | Mon Jun 20 1994 08:58 | 8 |
| One thing I like about film is you can do a little at a time and it's
clean and odor free. Painting requires bigger time windows and
protective equipment is a must! I like the ding resistance of painted
glass but I like the light weight of film covered balsa. It's a
difficult tradeoff if looks are at the top of the list.
Charlie
|