Fiberglass resin

Dark Shadow

Sr Member
RPF PREMIUM MEMBER
Where can I buy the best and most affordable resin for a gel coat? I plan on using polyester resin for the reinforcement but I need a good base coat that will offer a paint friendly surface. Please help...
 
There are a couple of gel coat distributers online, but most charge a lot for shipping because it's a hazardous substance.

You have two other options:

Look for boat and or car body repair shops in the phonebook. They're likely to have tons of gel coat in a rainbow of colors and might be willing to sell you some in small amounts for cheap.

The other option is to buy some bondo putty and mix it in small amounts with regular polyester resin. It will give you a nice sandable, paintable face coat. Just be sure to mix the catalysts from both the bondo and the resin into your mixture and don't let the face coat get too thick.
 
<div class='quotetop'>(weaselflinger @ Jul 6 2006, 03:51 PM) [snapback]1275361[/snapback]</div>
...The other option is to buy some bondo putty and mix it in small amounts with regular polyester resin. It will give you a nice sandable, paintable face coat. Just be sure to mix the catalysts from both the bondo and the resin into your mixture and don't let the face coat get too thick.
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Very interesting. I'm assuming the same mix ratio applies to both catalysts, even though they're mixed? Would the working times be the same before it starts to gel up?
 
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Very interesting. I'm assuming the same mix ratio applies to both catalysts, even though they're mixed? Would the working times be the same before it starts to gel up?
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Yes, the mix ratio stays the same. The speed at which it kicks depends on the variable amounts of everything. I use more bondo than resin and mix them fairly hot with catalysts so it tends to kick pretty quick.

Also, because it has an exothermic reaction, it tends to speed up the kicking rate of fiberglass/resin layers applied over the top of it.

The bondo/resin mixture should always be reinforced with fiberglass/resin. I received a couple helmets in trade that were not reinforced and they are brittle without the reinforcement.
 
I will be needing about a gallon of the face coat. I have heard of the mixing bondo with poly resin. Bondo has the polyester resin in it already so it makes sense. The one thing is that if you go the bondo/ resin route the face coat tends to shrink pretty quickly so putting that reinforcement layer in time is crutial. Any more suggestions?
-Scott
 
Another thing that would work is Talc (baby) Powder. Mix about 2 parts powder
to one part resin and you get a nice sandable gel coat. Mix in your hardner
as normal. You can even ad a tint base to the batch before you stir it and
this will show you that you batch has been properly mixed. You should get a
nice creamey mix. You want it a bit more pasty, ad more talc. I did this for
years prior to buying gel coat online.

Just a thought to those without a big budget. One trip to walmart and your set. LOL.
 
Why do my castings used with poly resin come out tacky for days. I have to douse them with silics powder to cover the stickyness so I can paint it. It works great but id like them to come out of the silicone mold ready to paint. Strance thing is that the waist in the mixing jars pulls out like glass and isnt sticky at all. Its the same stuff I layed in the mold. Only diff is one is being layed in silicone and the other is in a plastic jar. Whats up with this?
 
<div class='quotetop'>(Dark Shadow @ Jul 19 2006, 12:34 AM) [snapback]1283635[/snapback]</div>
Why do my castings used with poly resin come out tacky for days.[/b]

Polyester really just needs to be post cured in many cases...

Also...

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the silicone mold ready to paint. Strance thing is that the waist in the mixing jars pulls out like glass and isnt sticky at all. Its the same stuff I layed in the mold. Only diff is one is being layed in silicone and the other is in a plastic jar. Whats up with this?
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This is probably you biggest issue since you state that it cures outside the mold...

Polyester Resins from my experience just don't like being cast in tin cure silicone molds, you will have much better results with a platinum cure silicone or alternate mold substance...

You can also use wax based release agents, or even spraying the silcone mold with a coat of primer or paint prior to casting so that the polyester is not in direct contact with the mold...

Or gel coat, then cast...
 
If you are anywhere near a boat yard or the coast, check for boat building material suppliers. Most are helpfull if you talk to them in person and will give you some tips. They probably won't know squatt about casting it in a silicone mold but they can tell you proper ratios, types of glass cloths, additives like cabocil and other usefull items. When I was doing boat glassing, I found moisture in the air, heat and size of the mix all contributed to the glass not kicking just right. I used both poly and epoxy and liked the epoxy better, but it cost more.
 
dunno if this would be the place to post this but im gonna try to make a thin mask thicker,its a joey jordison mask that i bought off ebay,its one of those thin plastic ones,but its got the high forehead and the scars indented in,and it looks really cool,but it cracked on the lower right side cause its so thin,anyways i want to remake it for my own peresonal collection,but in fiberglass or liquid plastic or something of the sort,i cant vaccuumform it,i dont really know if it would look good in latex,but yeah how would i go about it?the whole moldmaking process and actual casting?
 
<div class='quotetop'>(Dark Shadow @ Jul 6 2006, 05:56 PM) [snapback]1275287[/snapback]</div>
Where can I buy the best and most affordable resin for a gel coat? I plan on using polyester resin for the reinforcement but I need a good base coat that will offer a paint friendly surface. Please help...
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My first question is: Do you need gelcoat?

There is no mention of what you want to do with it. If you could supply more information on the project, I can supply better informetion on the answer.

If you are going to paint this item, a good primer will work fine on fiberglass without getlcoat.

What is this for?
 
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