With the Gel coat or not

[supercha]

you actually should use MEK to thin or Duratec’s laquer thinner(never more than 10%) for gelcoats. never acetone because it makes it rubbery. I would recommend duratecs VE or PE high gloss topcoats they very thin and get a good bond with epoxy. does not need to be thinned at all. I actually wish it was a tad bit thicker and clearer. It being thinner though helps it flaten but its a pain spraying because you must mist coat the first coat or two before putting on a real coat.

YES, THANK YOU!!! When i mix my gel coat with the acetone it makes it rubbery. IT DOES NOT WORK.
I am talking about this product from FIBREGLAST.COM
Duratec Hi Gloss additive

One more question. Is that possible just to spray clear coat onto the mold like a gel coat and then just do infusion? After when part will come out from the mold, it will need to be clear coated 1-2 times
I did that and i got a very good finish. I took off this part from a flat panel today and it still need to be cleared. Here are some pictures.

[hojo]

duratecs hi gloss additive is suppose to be used with a gelcoat up to 50% mix, never straight. it is thin and will reduce the viscosity of your clear gelcoat greatly. you should not have to reduce anymore to spray from a normal gravity feed with a 2.5 tip. you can infuse on top the clear gelcoat but always do test panel prior to making your part to ensure proper adhesion, if you wait to long you will have to sand the gelcoat first. duratecs VE and PE clear topcoats can be sprayed without mixing with another gelcoat or thinning and will have a good bond with VE, PE and most epoxies. hope that helps, good luck

[supercha]

duratecs hi gloss additive is suppose to be used with a gelcoat up to 50% mix, never straight. it is thin and will reduce the viscosity of your clear gelcoat greatly. you should not have to reduce anymore to spray from a normal gravity feed with a 2.5 tip. you can infuse on top the clear gelcoat but always do test panel prior to making your part to ensure proper adhesion, if you wait to long you will have to sand the gelcoat first. duratecs VE and PE clear topcoats can be sprayed without mixing with another gelcoat or thinning and will have a good bond with VE, PE and most epoxies. hope that helps, good luck

Where can i get that Duratec VE/PE?? Does it have a CLEAR HIGH gloss finish? Basically, you are saying , i can take that Duratec VE and spray it straight onto the mold, let it cure , then sand it little bit and then it will be ready to do my infusion. Does it have a UV in it?
I have a 2.0 HVLP gun . Will it work?

[hojo]

Where can i get that Duratec VE/PE?? Does it have a CLEAR HIGH gloss finish? Basically, you are saying , i can take that Duratec VE and spray it straight onto the mold, let it cure , then sand it little bit and then it will be ready to do my infusion. Does it have a UV in it?
I have a 2.0 HVLP gun . Will it work?

Contact Duratec and ask for your local distributor it will be cheaper than buying off a hobbyist site. It has a higloss clear finish if sprayed thin but if you spray it too thick it will look brownish because its not completly clear unfortunatly. Scotch brite the surface before infusing. The higloss additive with a clear gelcoat will be clearer. Not UV stable, must be clear coated after if its going to be exposed to UV. 2.0 HVLP should work fine with either, fan might be a little small and youll have to spray slower

[supercha]

Contact Duratec and ask for your local distributor it will be cheaper than buying off a hobbyist site. It has a higloss clear finish if sprayed thin but if you spray it too thick it will look brownish because its not completly clear unfortunatly. Scotch brite the surface before infusing. The higloss additive with a clear gelcoat will be clearer. Not UV stable, must be clear coated after if its going to be exposed to UV. 2.0 HVLP should work fine with either, fan might be a little small and youll have to spray slower

I do not want to make a THIIIIK gel coat, i just need to sparay something onto my mold just to prevent fabric prints from the fabric. Basically, i want to spray 1-2 CLEAR as possible thin coats then let it cure 1-3 hours then do my infusion. My biggest concern is about mixind two different things when one cures faster than another one. I am thinking to use my infusion resin with that Duratec additive and see how it will cure.
Anyway, i will clear coat it after when i will take it out from the mold

[hojo]

the VE and PE topcoats will cure at 7-8 mils. you might find it harder to get the gelcoat that thin with the additive and cure correctly. also you should use MEKP-925H catalyst with the duratec for best cure.

[supercha]

the VE and PE topcoats will cure at 7-8 mils. you might find it harder to get the gelcoat that thin with the additive and cure correctly. also you should use MEKP-925H catalyst with the duratec for best cure.

Right! Here is the thing. That duratec uses 1-2% MEKP to cure, my Epoxy is using 2 parts “A” with a 1 part “B” curing agent.
I am thinking, if i am going to mix all these things together,what will happen?! Another thing, if a gel coat is using MEKP to cure. At that point i can mix them
Have you ever tried just to do your infusion with out any gel coat?

[hojo]

Right! Here is the thing. That duratec uses 1-2% MEKP to cure, my Epoxy is using 2 parts “A” with a 1 part “B” curing agent.
I am thinking, if i am going to mix all these things together,what will happen?! Another thing, if a gel coat is using MEKP to cure. At that point i can mix them
Have you ever tried just to do your infusion with out any gel coat?

you do not want to mix those together. you can mix the additive with a PE or VE gelcoat, but not with any epoxy. you would spray your gelcoat in to the mold let it tack up and place you material and infuse or if you waited too long you need to sand with atleast scotch brite. You can just infuse with no gelcoat and clearcoat it after, youll get the clearest finish that way. but you may find your mold to dirty quickly any may even have the epoxy attack your mold surface if not properly released.

[supercha]

you do not want to mix those together. you can mix the additive with a PE or VE gelcoat, but not with any epoxy. you would spray your gelcoat in to the mold let it tack up and place you material and infuse or if you waited too long you need to sand with atleast scotch brite. You can just infuse with no gelcoat and clearcoat it after, youll get the clearest finish that way. but you may find your mold to dirty quickly any may even have the epoxy attack your mold surface if not properly released.

I do not want to ask some stupid questions, but what is a “PE or VE” gelcoat?
Here is what i am doing. I am waxing my mold 2 times then spraying a PVA. Let it to cure 3-4 hours then spraying 2 coats of a regular UV clear coat. When everything is cured, i am laying up my materials and doing my infusion. The only thing i do not understand, why i can not do that in to that way when i can get a CLEAR high gloss finish?!
After 48 hours, i do a wet sanding (1500 sand paper) then spraying 2 more coats of clear
By the way, i newer sand my gel coat in the mold (which is a regular clear coat) It sticks VERY WELL in to my infusion resin

[hojo]

I do not want to ask some stupid questions, but what is a “PE or VE” gelcoat?
Here is what i am doing. I am waxing my mold 2 times then spraying a PVA. Let it to cure 3-4 hours then spraying 2 coats of a regular UV clear coat. When everything is cured, i am laying up my materials and doing my infusion. The only thing i do not understand, why i can not do that in to that way when i can get a CLEAR high gloss finish?!
After 48 hours, i do a wet sanding (1500 sand paper) then spraying 2 more coats of clear
By the way, i newer sand my gel coat in the mold (which is a regular clear coat) It sticks VERY WELL in to my infusion resin

PE is polyester, VE is Vinylester. Personally I do not like PVA at all. your best to use just wax or even better semi permanent sealers/release. Im a little confused on your exact process but if its working for you than thats great go for it. If your asking why your part isnt shiny out of mold it is probably from the PVA, just waxing or semi’s will fix that. the higloss additive will only work with PE and VE gelcoats not clear coats or epoxies. Im not too sure why your sanding with 1500grit paper then clear coating again, you should either sand with 400 grit and spray with clear or sand up to 2000+ and polish.

[supercha]

PE is polyester, VE is Vinylester. Personally I do not like PVA at all. your best to use just wax or even better semi permanent sealers/release. Im a little confused on your exact process but if its working for you than thats great go for it. If your asking why your part isnt shiny out of mold it is probably from the PVA, just waxing or semi’s will fix that. the higloss additive will only work with PE and VE gelcoats not clear coats or epoxies. Im not too sure why your sanding with 1500grit paper then clear coating again, you should either sand with 400 grit and spray with clear or sand up to 2000+ and polish.

Okay, i understand right now.
I am using 1500 grit paper, because my “gel coat (clear coat)” is thin when i am taking off from the mold. To make the surface little bit thicker and more shinier, i am sanding a little bit then spraying more clear coat. If i will use a 400 grit, i will damage CF under that clear coat.
Why you do not like PVA?? It helps me alot to prevent any epoxy sticking in to the mold. Also, demolding process is very easy

[aga]

pva is a great solution, but if you have a mold with a perfect surface, sanded and polished, wax will always leave a better surface, and demold easily too. personally i use pva when i make molds out of parts and want to protect the originals. after that i sand and polish the mold, and apply wax.

[Fastrr]

not to start a dispute so if NOT using acetone works for you then good. I have thinned clear gel coat with 5% acetone and had no problems with the hardness or finish.

If MEK works best then stick with it.

[Fastrr]

I wish i had some PVA here aga and my preval sprayer. I need to gel coat a plug and i don’t want the gel to fully cure on the surface. I don’t want to go thru the whole process of duratec clear or duratec primer.

Once i have a shop again i’ll switch over to Duratec products for plug coating.

[galway]

Have you ever tried just to do your infusion with out any gel coat?

Yes and once you find a semi perm release that works well for this the parts pop out easily. Once the parts are coming out good with no pin holes you will clear coat them after wards easily with great success.
I experimented with this for a while as i wanted to skip the gel coat part. Marbocote make a semi perm specifically for use on a mould being used for infusion without first spraying on gel coat.
hope that is of some help.

[supercha]

Yes and once you find a semi perm release that works well for this the parts pop out easily. Once the parts are coming out good with no pin holes you will clear coat them after wards easily with great success.
I experimented with this for a while as i wanted to skip the gel coat part. Marbocote make a semi perm specifically for use on a mould being used for infusion without first spraying on gel coat.
hope that is of some help.

That is very interesting, but, how strong will be the top coat with the clear only?? I think, all these gel coats are much stronger than clear coats.

[supercha]

I got my gel coat today , it is a Polyester gel coat. I mixed with the accetone (5%) then sprayed. The only thing, i have some orange peel on the surface.
I think my air pressure was high-65psi
I am using a 2.5mm tip HVLP gun
Also, the outside temperature was 68 degree today
It looks okay, but i think i can spray better.
One more thing, i just sprayed ONE THICK coat. Could be that the problem?
What is the best way/steps of spraying a gel coat?

[aga]

You can’t avoid orange peel on gelcoat, it’s to thick to even out. i dont know about using the duratec additive though, since that thins it out, it may level out better.

[MoPower]

not to start a dispute so if NOT using acetone works for you then good. I have thinned clear gel coat with 5% acetone and had no problems with the hardness or finish.

If MEK works best then stick with it.

technically, the textbook “correct” thinner to use is styrene but I’ve also used small amounts of acetone and other things with no problems but I was told that the physical properties will be diminished somewhat if you do that.

[MoPower]

I got my gel coat today , it is a Polyester gel coat. I mixed with the accetone (5%) then sprayed. The only thing, i have some orange peel on the surface.
I think my air pressure was high-65psi
I am using a 2.5mm tip HVLP gun
Also, the outside temperature was 68 degree today
It looks okay, but i think i can spray better.
One more thing, i just sprayed ONE THICK coat. Could be that the problem?
What is the best way/steps of spraying a gel coat?

The best low budget way to spray gel coat smoothly is with a pressure pot but you have to watch out not to let it kick in the bucket or you may sorry, hoses are not cheap to replace either. The pressure pot gives you a very smooth surface and will also eliminate the porosity problem that you would get with a dump gun. Also, there is no need to reduce the gel cote if you use a pressure pot. I always spray my tooling gel that way and get great results with no porosity.