The gun on ibferglast.com is a very popular gun. I think i know which one u are referring to. I found that same gun for like $130ish.
I guess ill buy it and see what happens. Maybe ill try brushing on for one mould
Brushing will work fine, but a good idea to read up on the recommended methods of doing this, if you are new to composite work.
Spraying with cup gun is faster and easier to do than brushing though, and may well be a better option for anyone not wanting to bother with the more involved brush application process.
well I am about to bite the bullet and pick up a cup gun for $150 shipped. what I want to know is:
will any generic cup gun spray all types of gel coat? even some heavier epoxy gel coats?
are there any disadvanatages to using a cup gun?
where can I read more about how the cuo gun works?
The tip is what determines what you can spray, which is easily changed in seconds. Don’t spray epoxy gel coats. It will constantly drip if pointed down.
Might be a good idea to get hold of a few books on composites and have a good read. Spraying epoxy is something that can be extremely damaging to your health, but maybe not something that is very clear?
yes, I have heard the same thing about spraying epoxy, its very bad. epoxy gelcoat should always be applied by hand
I’m in the same position, trying to choose a gun… Will the cup gun work well for spraying gel on finished parts or is it better used only in mold constructing parts?
There should be no need to spray gel on finished parts, but you may need to spray clear coat, which a cup gun is going to struggle with.
Sorry, didn’t explain myself correctly… I’m wondering about using one for gelcoat re-spraying on boat repairs or building fiberglass parts not using a mold process.
As Chinese HVLP guns with a selection of air caps. material nozzles, and needles, are very cheap, why not have an HVLP gun as well as a cup gun? You will probably find the HVLP is better for some jobs, and the cup gun for others.
So classic
Do u think that any cup gun will do the trick? Im ready to start spraying gel coat at this point.
As I suggested in my previous post, HVLP guns are very cheap, so why not try one, as well as a cup gun?
If you want to surface finished parts say, then using Duratec clear, sprayed with an HVLP gun is going to be faster than spraying the same material with a cup gun, as the HVLP will atomisatise the thinner Duratec material better than a cup gun, provide a smoother finish, which means less final finishing.
Good advice, thanks! I know I’m going to have to step up and just get started… just so worried that I’m going to ruin any gun by letting the gelcoat go off in it. Any gun I might ruin (cheap or not) is going to hurt. 
Thats a very good reason for using a cup gun or in some cases a brush to apply gel-coat…
If you want to surface coat a finished part, with something like Duratec clear, then an HVLP gun is probably the best choice, as this will provide a better finish, and you will have a lot less sanding to do.
If you have larger moulds or multiple smaller moulds, used for GRP parts, gel-coat application by cup gun is the best choice.
Finally if you want to make limited numbers of parts using smallish moulds, then properly brushed gel-coat will work just fine, and save cost and clean up time.
I think that most people complaining about the cup gun are still using the #6 nozzle that comes with it. It works for unthinned gel coat and thick primers, but nearly impossible to avoid orange peel.
With #4 and #5 nozzles I can spray Duratec coatings or Gel Coat, with additive, and achieve a very smooth application. 20-25 psi helps.
Thanks guys… confidence going up!
Im going to buy the gun but wanted to ask:
Is the
ES g100 really a good gun? found here:
http://www.jamestowndistributors.com/userportal/show_product.do?pid=6835&familyName=ES+G100+Gelcoat+Spray+Gun+
Ebay actually has this gun for $120 which is a cheaper than jamestown distributors
I am comparing it to: the g200 which is externally mixed found here:
http://cgi.ebay.com/G200-6-External-Mix-Gel-Coat-and-Resin-Spray-Gun_W0QQitemZ300076157268QQcmdZViewItem
US COMPOSITES has them for 120 also
Hey…relax. You guys probably have the makings of a really good (cheap)gel coat gun laying around. Put one together. This is one I made many years ago. Still kickin…
You adjust the “pot pressure” to help push out the high viscosity
material.