Conference vicki::boats

��       <<< Note 1212.0 by FOUNDR::DODIER "Single Income, Clan'o Kids" >>>
��                         -< Fiberglass boat building >-

��    	Has anyone in here ever tried to build a fiberglass boat ? I was
��    just wondering what is used as a release agent so that the fiberglass
��    doesn't stick to the form.

    There is a standard product for this 'mold release'.   This
    works great if you have a perfect mold, with a 'mirror'
    finish -- either polished metal or gel coat.

    I built a fiberglass tank, and used cardboard as the plug.
    Mold release woulnd't have worked over the cardboard, as
    it wasn't smooth enough.

    I got a big chunk of wax, like the folks in the 60's used to
    mold candles.   

    I melted the wax, and painted it on the mold.  You can smooth
    it with a a heatgun, or a flat piece of heated metal -- as
    sort of a hot putty knife.

    Cheap, and worked great.

    Why build a boat?  You won't save any money...

    	I was thinking of building a pontoon type paddle-wheel boat. They
    run about $400 new at Sam's. I'm pretty sure I can build one for less 
    than that, but I also enjoy puttering with things like this.
    
    	After thinking about this, rather than use a form, I was thinking
    of just building the pontoons out of built up styrofoam (sheets cut,
    glued, and shaped) and then just fiberglass over it.
    
    	Ray

��    	After thinking about this, rather than use a form, I was thinking
��    of just building the pontoons out of built up styrofoam (sheets cut,
��    glued, and shaped) and then just fiberglass over it.

    If you want to fiberglass over foam, you'll have to use epoxy
    resin.  Polyester resin will disolve the foam.

    Epoxy resin is way more expensive than polyester resin.

    Careful!  Polyester resin will damage Styrofoam, (melt or solvnet
    attack).  You can prevent this by using a barrier coat of epoxy resin
    on the foam, ans let it cure.  Then you cna put on traditional
    fiberglass.  You probably don't need mold release, as you are making
    the actual part.

    	I knew that I would need the epoxy resin. I wasn't aware that it
    was *much* more expensive than the polyester resin. So what does a
    gallon of epoxy resin go for, roughly ?
    
    	I priced out some of the items at Home Depot. The foam for the 
    pontoons will run me about $20. I was thinking about making the 
    body itself from PVC conduit with a pressure treated deck (either
    plywood or 5/4 radius edged, covered with indoor/outdoor carpeting.
    The PVC would run me about $30 and it's about $35 for PT plywood.
    
    	The drive-train will come mostly from used bicycle parts. With
    other misc. things, I expect it will run me under $200.
    
    	Ray

re .4:

A word of caution: epoxy bonds well to cured polyester resin. Polyester
resin does not bond well to epoxy, so you'd probably should not try
covering the initial layer of epoxy with polyester. 

re .5:

Epoxy resin is not inexpensive. There are many suppliers whose prices vary 
somewhat, like $30 to $40 per gallon in 5 gallon pails. Price per gallon 
is higher if you buy only a gallon or two. You could well use several 
gallons. You might want to read one of the introductory books on 
fiberglass boatbuilding before buying supplies. The one I have gives 
estimates of how much resin is needed for various layups. 

Alan

    	I got another thought I was sort of kicking around. If I put a
    board across the front and back, from pontoon to pontoon like so -

    			 ---         ---
    			|   |-------|   |
    			|   |       |   |
    			|   |       |   |
    			|   |       |   |
    			|   |       |   |
    			|   |       |   |
    			|   |-------|   |
    			 ---         ---

    	...and placed it on back sloping angle, this would create a big air
    bubble for additional flotation. More importantly, I was thinking that
    if I did this, I could try drilling a hole just large enough to stick
    my leaf blower in.

    	If I put the boat on a flat surface and could get it to create an 
    air bearing (i.e. Hovercraft), this would be one wild paddle-wheel boat.
    The other thought I had was that since one of the bikes that I'm going
    to use is a 10 speed, I may try to utilize the derailers.

    	On a normal paddle-wheel boat I would expect the derailers to be
    nearly useless. Once the optimal gear is found there'd be little
    benefit to being able to shift gears, but on a near frictionless 
    vehicle...hmmmmm.

    	Ray

	   Please be aware that along with the various chemicals that are
	needed to both do the work and the appropriate solvents for clean-up
	you also have the responsibility of proper storage and disposal of
	all this stuff.

				B.C. (who used to build fiberglass boats
				      and can't understand why anybody would
				      play with this stuff if they don't
				      -have- to.) 

    re:-7
    
    	Please excuse my last reply. I have some strange thought processes
    before my morning coffee ;-)
    	
    	I have done some fairly extensive body work using polyester resin
    and fiberglass cloth. I know what a pain this stuff can be to work with. 
    I typically use cheap brushes and throw them away rather than clean them.
    For a project this size, I'll likely use rubber gloves and throw them
    away when done also.
    
    	Ray