Low Cost Gun for White Epoxy (need help with conclusion)

C

Chris Martin

Promoted Users
I have been doing a bit of reading on the forum about inexpensive guns (I need a gun to shoot last coat of white epoxy on one project which is the last coat until top coating in a year from now). Lots of info but need help reaching a conclusion specific to the epoxy.

I have been using a cheap Amazon PNT 1.4 and results are OK but wonder if it could be better for that last coat. The issue I am having is it seems to apply a too thick a coat (trying to go thin on first pass). I can close the fluid but seems it sprays a little gritty (reducing at 10% but will try a little more reducer today).

Seems people like the Vaper and Global brands. I can get the Vaper 19114 HVLP 1.4 (is this one any better than the cheaper blue one?) if I drive 50 miles to northern. Could buy the Global at amazon and not drive the 50 miles but want to go for the best of the two.

I am also not against spending up to $120 on a gun if it would make a difference. Saw a nicely cared DeVilbiss A-13 Starting Line on eBay for $100 but don't even know if this gun is OK for epoxy. A little afraid of buying older used guns (seems to me not all older guns work well with today's materials).

BTW, I have a nice older Sharpe SGFHVLP 1.4 I bought new eons ago. Spayed Durathane superbly back in the days but this epoxy not so much. Doesn't seem to fan enough.

What do you guys think?

Thanks,
Chris
 
One last question (not SPI related). I got some devilbiss gun lube. Is that stuff OK to sparingly put in the gun or can it contaminate it? Had issues after I first used it but I don't think where related to the lube.

Thanks for the help,
Chris
 
chris, personally i think your wasting your money buying a better gun. my question to you is why do you need a really smooth and good looking final coat of epoxy if its just going to sit around for a year then just get sanded down, more epoxy put on and top coated? really, who care what it looks like. its not the topcoat. epoxy is a functional coating. its not meant to look really nice.

been using devilbiss gun lube for 20 years. never an issue with that stuff. a little on the needle, springs and seals. after you assemble your gun always spray a couple oz of acetone or reducer through it to clean out any that got in the air or fluid passages.
 
Thanks Jim. Very useful info.

To answer your question of whether it is important how the epoxy will look the answer is "no" and "yes". My project is a composite airplane (lets first clarify that although it's and airplane I'm not rich :) ) so "yes" we would like it to look half decent even if on primer.

So the "no" part of the answer is that you are right the epoxy will be sanded at some point and I will have a pro finish spraying the top coat (with a coat of epoxy first) with real equipment. The "yes" is that after seeing how nice the SPI epoxy looks I am now shooting for the best finish I can get. So far the finish is very good (a bit satin-ish which is exactly what I want) but it just takes a bit of effort to make it this nice with my guns so I was hoping a different 1.4 (or 1.3) gun would spray a little thinner and better).

The Amazon PNT gun with a 1.4 tip I have is not that bad but it's seems it doesn't atomize that well (I think) so on my last part it orange peeled in one fist size spot because its going on heavy as much as I try not to. The pattern is good. I am going to spray some parts right now and I am upping the reducer to 20% or 30% instead of 10% and will shoot it with my good Sharpe SGF for the last two coats and see what happens. That gun sprays nice but the pattern is kind of small making spraying large parts a real job (and I still haven't done the wings).

I am also shooting Regular 2K (nice stuff compared to what I was using before, thanks SPI) with the cheapy PNT with 1.8 tip and its just fine since I am really sanding 95% of it off.

Jim, I think I read one of your postings indicating you liked the Global guns for primer. Is that so?

Thanks,
Chris
 
if you can find a 3m accuspray, they are great for the epoxies. really nice fan for the gun. I know its not technically cheap, you can find them on ebay for about 100, but swapping the caps from 1.2-2.0 without needing all the cleaning and disassembly if you do not use it often makes for a good gun. Most of the finex stuff is ok on amazon, got a neiko that was ok with the 2.5 tip for slicksand, but they really clog quickly with epoxies. Theres a place in wisconsin that has the atomizing heads in all sizes for about 20 for a pack of 4.
 
anotheridiot said:
if you can find a 3m accuspray, they are great for the epoxies. really nice fan for the gun. I know its not technically cheap, you can find them on ebay for about 100, but swapping the caps from 1.2-2.0 without needing all the cleaning and disassembly if you do not use it often makes for a good gun. Most of the finex stuff is ok on amazon, got a neiko that was ok with the 2.5 tip for slicksand, but they really clog quickly with epoxies. Theres a place in wisconsin that has the atomizing heads in all sizes for about 20 for a pack of 4.
Click to expand...
I 2nd the motion on the Accuspray, I can lay down Universal much better with it than my Devilbiss Millenium or the new Copper I bought a couple of years ago on the "Gunman's" recommendation. Love the versatility too. Also it is really easy to cleanup when yur dun.
 
Thanks to all for the replies. I will look into the Accuspray line. Thanks.

This afternoon was very educational. I shot two small panels with 1:1:30% on my Sharpe 1.4. Flowed like silk and dried with a little satin as I like. But is way too transparent. But the application was perfect.

I did further reading on the forum this evening and learned a lot more about epoxy issues. What happened to me with the orange peel spot you experts call cratering for applying too heavy. I am sure it was gun getting too close at that spot since the rest of the large part I painted came out perfect. I do think I am holding my gun too close to the surface (around 5-6 inches). Will try to go a little farther away. Maybe also the reason for my small pattern on the Sharpe.

So tomorrow I am going to shoot another large component. I am going to use my cheapy PNT 1.4 and go back to 10% reduction since this is for a second stabilizer and want it to match the looks of the first. Will try 15% in the future to see if I can find a balance between flow and transparency. Will crank my booth regulator a little higher and pay A LOT more attention to my gun distance.

Quick question: I understand the consequences of low gun inlet pressure on cratering (I'm running at 25 psi) but how can you tell you got the pressure too high?

Thanks again. I'm very close to taming this epoxy!
Chris
 
First epoxy coat is most sensitive to being too thick.
Any gun with pressure assisted gravity feed will help thicker liquid spray better with far less turning into overspray. i think many of the accuspray guns have this, though their quality isn't the greatest. I've used a 6 stage titan capspray turbine setup not even marketed towards automotive use. Can use a smaller tip size than typical gun with the pressure assist & did great with both epoxy & especially g-2 primer surfacer. Not a budget setup though.
The 1.8 vapar is ok, just throw away the internal sprayer in ANY gun first.
 
Don't shoot the messenger and be advised I'm a rookie, but I shoot all my primers through a Harbor Freight gun. The link below is what I have. Kit comes with two guns the larger of which comes with both a 1.4 and 1.8 needle assembly. My SPI epoxy is of course shot through the 1.4 and their 2k through the 1.8. Both the epoxy and the 2k lay down nicely with this gun. I gave less than $50 for this kit. And, as such, I don't worry too much about ruining it by doing something stupid like not paying attention to the POT life of SPI 2k. Yeah, had it harden up in this gun and spent some time cleaning it up. Would not have been happy had this happened in my Devilbliss.

https://www.harborfreight.com/professional-automotive-hvlp-spray-gun-kit-94572.html
 
Again thanks to all for the tips. I seriously considered the Accuspray but by the time I get the kit, liners and additional tips it racks up. I was tempted and I’m sure worth it but I only have a few parts to spray and after all it is primer. Maybe if when time comes to top coat I decide to do it myself I’ll get a better gun.

I ended up ordering a TCP global G6600 1.4 with an additional 1.8 nozzle. $80. we’ll see. I choose the Global because they seem to have support for parts and nozzles. And northern is a bit far for me.

With that said I shot a larger part today and it came out great. Paid more attention to gun distance, increased the pressure a little and much better. A hair in the dry side (my eyes are not what they where 25 years ago when I could paint) but I’m getting there.

Thanks again.

Chris
 
Happy with the end result! Too bad I learned about SPI epoxy after I used some other PU sealer on the fuselage. As you can see they don’t quite match. Oh well.
 

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