Need Fiberglass Advice

Ralph 123

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Jun 24, 2003
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Need Fiberglass Advice

I need to make some arm rests for my bench seat out of fiberglass. Each arm rest is 21" X 10" X 5" or so. In the arm rests I am going to mount rod holders and maybe a cup holder.<br /><br />What is the best material to use for the form? Can I sculpt Styrofoam and then glass over it? <br /><br />What type of glass mat and resin should I use?
 

CTD

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Nov 13, 2002
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Re: Need Fiberglass Advice

Re: Need Fiberglass Advice

For something that needs strength I would build it out of wood. If it looks good leave it wood finish if not glass over it. Best is epoxy, if you need to add a lot of strength otherwise use polyester.
 

crab bait

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Re: Need Fiberglass Advice

Re: Need Fiberglass Advice

styrofoam.. but it's alot of messy itchy work..<br /><br />i made an o/b cover for a old chrysler onetime.. spray glued up layers of foam sheets then cut/sanded out the shape.. <br /><br />wrapped with saran wrap as per release..<br /><br />layed up layers of cloth maybe six..sanded the nasty/ugly thing until looked good ..<br /><br />applied 'bondo' to finish.. then more sand paper.. <br /><br />prime & paint..<br /><br />look good .. alotta work.. <br /><br />did it cause i couldn't find one to buy..<br /><br />only did it by 'grit-teeth-hardhead' detrmination.. <br /><br />take my word.. make it outta nice mohogany.. alittle custom wood on a boat,, is so awlsome..!!
 

LubeDude

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Re: Need Fiberglass Advice

Re: Need Fiberglass Advice

If you use the styrofoam method, dont let any touch the raw styrofoam, it will desolve it in short order! I think I would make them out of some mohogany and put teak oil on them. they would look great!
 

kd6nem

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Re: Need Fiberglass Advice

Re: Need Fiberglass Advice

I do agree the wood would have a great appearance and would be quicker and easier. However if you really must do the foam core fiberglass method use the proper type foam core for the type resin you'll use. A few types here are for exactly this purpose, or rather to become the permanent form for airplane wings: aircraft spruce and supply <br />Might even be able to scrounge some from equipment packing material or used urethane foam in a can if you're clever. The resin compatibilities are listed- e.g. polystyrene (styrofoam) will indeed melt in the presence of polyester resins, but not epoxy. I suppose regular styrofoam might be OK if used with epoxy?
 

BillP

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Re: Need Fiberglass Advice

Re: Need Fiberglass Advice

If you are using the foam for just a mold, cover it with saran wrap before glassing. That will protect the foam from melting with polyester resin and provide a release. If the foam is structural use epoxy resin. <br /><br />Epoxy works over every type foam you can find.
 

Ralph 123

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Re: Need Fiberglass Advice

Re: Need Fiberglass Advice

That was just the sort of heads-up advice I was looking for. Thanks guys!<br /><br />I can't use wood because the bench seat is also the engine cover and has to be lifted for access to the engines. It is already too heavy and adding wooden armrest out of hardwood wood be just too much added weight I think.<br /><br />What type (weight, weave) and epoxy would you all recommend?
 

Bondo

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Re: Need Fiberglass Advice

Re: Need Fiberglass Advice

Hi Ralph,<br />Thanks to your 'puter advice, I'm Happy Now......This new Dell is Smoking....... ;) <br /><br />Lots of Great Advice on this thread.....<br />For Epoxy, the Cheapest is the Best.... I've seen at at around $30. to $35. a gallon......Try here;<br /> http://www.epoxyproducts.com/marine.html <br />Or here, http://raka.com/ <br />Or here, http://www.shopmaninc.com/ <br />Or here, http://www.fibreglast.com/ <br />Or here, http://www.mertons.com/ <br />Or here, http://www.fiberlay.com/ <br />Or there's Always, http://www.westsystem.com/ <br /><br />For the structure you're looking for, 14oz. would be plenty, maybe a couple layers.... and, it'll still be plyable enough to work it around corners or what not.......<br />You can go to a 2oz. angel hair mat, for a final layers, this would help block out the Weave of the heavier cloth beneath.... a little less sanding maybe......<br /><br />Another method of lay-up, rather than a Foam Form, You can mock-up the shape you need out of Cardboard, Then cover it with glass........<br />You can build thinner panels with the pressedboard.......<br />Polyester doesn't Desolve Cardboard...<br />That'll lower your costs......<br /><br />Good Luck............. :D
 

crab bait

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Re: Need Fiberglass Advice

Re: Need Fiberglass Advice

if'n your layin' up fiberglass on a mold.. i'd diffenately use polyester resin an not epoxy.. poly excells at this mode.. <br /><br />i'd use 7.5 oz cloth .. the poly cames in waxed an non waxed.. i can't remember which one to use for lay-up.. <br /><br />ask at were you buy.. they'll know.. <br /><br />good luck ( hate-to-be-you ;) )
 
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