Fiberglass Resin?

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Aiden26

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Hey guys. I'm in the process of Fiberglassing my very first helmet and there's a couple things I would like to sum up. Number 1, what's the consistency of Fiber resin supposed to be? When I was using the Resin, it was a bit thick. Also, the fiberglass Resin didn't go throw to the other side. So would I have to resin the inside or go straight to using rondo? Thanks!
 
In order to help out, I'll need to ask a few questions.

First, what kind of fiberglass are you using? Mat or cloth? If you're using mat, I would suggest switching to cloth, since mat is a bit heavy for applying to a helmet. Regardless, my ultimate suggestion would be to slush a layer of rondo on the inside of the helmet prior to applying fiberglass. This gets all the tiny crevices filled in, and will help prevent air bubbles when glassing.

Second, how are you applying your fiberglass? My method involves coating a section of the inside of the helmet with resin, placing a strip of fiberglass cloth in the wet resin, then dabbing the cloth with the same brush used to apply the resin until the resin is soaked through (adding more to the top of the fiberglass cloth if necessary). I take care to work in small sections.

Last, how are you mixing your resin? You mentioned that it was thick when applying it and not soaking through the fiberglass. You might be adding too much hardener, causing it to set up too quickly. When applying resin, it should have the consistency of warm honey (a bit thinner than honey at room temperature), and should flow pretty easily.
 
In order to help out, I'll need to ask a few questions.

First, what kind of fiberglass are you using? Mat or cloth? If you're using mat, I would suggest switching to cloth, since mat is a bit heavy for applying to a helmet. Regardless, my ultimate suggestion would be to slush a layer of rondo on the inside of the helmet prior to applying fiberglass. This gets all the tiny crevices filled in, and will help prevent air bubbles when glassing.

Second, how are you applying your fiberglass? My method involves coating a section of the inside of the helmet with resin, placing a strip of fiberglass cloth in the wet resin, then dabbing the cloth with the same brush used to apply the resin until the resin is soaked through (adding more to the top of the fiberglass cloth if necessary). I take care to work in small sections.

Last, how are you mixing your resin? You mentioned that it was thick when applying it and not soaking through the fiberglass. You might be adding too much hardener, causing it to set up too quickly. When applying resin, it should have the consistency of warm honey (a bit thinner than honey at room temperature), and should flow pretty easily.

I'm using Bondo Fiberglass Resin. Like I mentioned I'm using rondo. Before doing this I did some research, a 405th member said to use 10 drops of hardener for 1 ounce. I used 2 ounces but only used 17 drops.
 
How hot is it where you are mixing the resin? I've had resin and body filler harden within minutes when it was excessively hot outside.
 
How hot is it where you are mixing the resin? I've had resin and body filler harden within minutes when it was excessively hot outside.

You know what? I actual don't remember it getting hot at all O_O.... It could be the gloves I was wearing. The material and thickness could have prevented the heat coming through.
 
The resin will get hot as it goes off, if you mix large amounts it can get VERY hot, in fact it is possible it can set fire to things.
It's recommended that any excess resin is spread out to prevent heat build up.
Outside temps will effect the setting time of the resin but not massively I believe.
 
I'd also like to mention that if you poked the hole in the harder container too wide, it will be hard to gauge what a drop is. I was using one hardener container, 20 drops per 2 ounces of resin, and it worked great. Gave me a good amount of time before hardening and it hardened well with no left over smell or tackiness. I moved on to a new container of hardener and I think I cut the hole too big. 20 drops hardened the resin in a couple minutes. Took me a few more attempts to get the right amount of drops for this new container, 12.

I have resined both the inside and outside of my pep pieces. Used a lot more resin in areas that have details that fiberglass won't work with. You could use rondo for these areas too.
 
Something iv found works is mix the resin with talc powder to form a paste that you can then use to fill small gaps or use as a filler for 90 deg bends on the inside of the piece where you will struggle to get the fiberglass matt or cloth to conform properly. you can get glass powder to do the same thing but it costs a fair bit and the talc/resin mix is still very tough... much tougher than body filler.
 
Body filler is resin and talc. Well, mostly. There are a few other things, but those two make up more than half the MSDS.
 
Most amazing using talc with the resin. It not only took a great shape but also filled in the nasty little holes you get when two pieces don't align all that well.
 
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