quick epoxy question

S

Steves69LS3

what does it mean when you have tiny dimples in your paint after spraying?
they arent open, just tiny needle tip sized dimples. i have cleaned thoroghly with waterborne W&G remover. could it be too high of pressure at the gun? im using a cheap hvlp with a 1.4 tip

thanks guys

Steven
 
What are you running to get the moisture out of the line?
Is it a clean dedicated to painting only hose?
Did you clean your gun, even though new, before you used it.
What kind of filters are you running?
 
i have a moisture/filter canister10 ft from the compressor and am using a dessicant dryer at the gun. after every paint session i totally disassemble my gun for cleaning. and always adjust fluid and fan before every use.
 
btw do i have to reshoot? or can i go about buisness and sand and apply filler?

thanks guys
 
I'll let the guys who have the knowledge answer.
I just have found those to be the common questions that get asked first from those that have the answers. :D
 
If you seen these dimples on your first pass and they appeared to be a contamination issue as in fisheyes and if it was a lot of them then I would remove the epoxy, re-clean, and start over. But if these are just small dimples that happened during application on the surface I wouldn't worry about it-move on to your next step. Some induction time also helps the sprayability of the epoxy also and it likes good atomization from what I've seen, maybe Barry will chime in.
 
If they show up in the first coat it is always one of the three.
To low air pressure.
Wax and grease remover still in pores of metal.
Water vapors in air line.

The above is under the assumption that there is not a contamination issue.

If in second coat:
Water vapors in air line.
Two low air pressure.
Not enough flash time.

Testing of this has showen, that the epoxy will cure out and bond well AS LONG as it is not a contamination issue, cure just may be slowed down a few days.
 
i didnt notice if it happened on the first coat. my pressure with trigger squeezed is 30psi i let it flash for around 15 minutes
 
to try and solve any problems in my air line the old line i had ran from the tank and up over my garage door to a cannister dryer/filter and then to a 25ft hose reel. the line that ran from the compressor is 50ft long and old and even may have seen some oil in its lifetime. so i replaced it with 2 8ft sections of hose now it goeas from the tank up over the garage door where now it meets a water seperator/ filter then a line runs from that to the cannister dryer/filter. i set the water seperator on a low point so that any moisture will fall to it. and its also good to replace 50ft of hose with ony 16ft. hopefully this will help with any line contamination.
 
today i sprayed epoxy on my fiberglass rear spoiler from my 69 camaro. first i scuffed the whole thing. then washed it with dawn liquid soap. dried it completely and used waterborne w&g on it until my drying rag was completely clean. then i mixed some epoxy letting it induce for an hour as well as letting the spoiler sit and air out for an hour. then i tacked the spoiler off and for the first time i get to use my new SATA 4000 B RP digital spray gun with a 1.4 tip. I freekin love this gun!!! it is very quick and very controllable. so then i proceeded to lay down the first coat. no visible problems so far. then i waited around 15-20 minutes flash time and laid the second final coat. again no visible problems. i am even more happy now that i think i have solved the dimpleing issue. the epoxy dried as smooth as glass to bad i have to cover it with filler to smooth out the production ripples on it :)
 
It seems to me that there are a number of these threads that all mention fish eye type problems and the commom denominator is some cheap chinese knock off gun having its air passage contaminated with oils.
 
I've read here that it's recommended to clean any new gun whether cheap or costly.
 
could the cause be that i use lacquer thinner to clean my guns??
 
Steves69LS3;13631 said:
could the cause be that i use lacquer thinner to clean my guns??
Click to expand...



I don't think so, lacquer thinner is most likely the most used gun cleaner out there.
 
im still getting those tiny little dimples. i have all new air hose, i have set up all black iron piping with risers to a devillbiss QC3 filter my gun is super clean and i let the epoxy induce for at least 30 min and metal temp is over 60 degrees and thoroughly cleaned and i let it sit as the epoxy induces. and usually wait 15 min between coats. i do wety sand the panels with 400 grit before i apply filler so maybe its no big deal
 
Some of the lacquer thinners out there are recycled garbage full of who knows what, I've had some that was blue colored, some with a brown tinge.... They work fine for basic cleaning but rinse it out with some urethane reducer before you load the epoxy.
 
You might also want to try some of the new formula epoxy. Here is what Barry had to say.


Barryk




Paint Fanatic
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Join Date: Aug 2010Location: Canton, GAPosts: 1,056






There are a lot of issues here that can effect the epoxy and most of them have been pointed out in some previous posts and all the statements are true.

The first problem is the epoxy is thicker then most standard epoxies out their and like any problem, mils can be a contributing factor along with flash times, temperature, humidity, and right down to the gun and tip size being used.

One thing I will not do, is lower the viscosity of the epoxy as mils are also very important with an epoxy for corrosion protection and adhesion but I have also known as SPI has grown in the Do-It-Yourself and and learning applicators for some time now, that I need to do something and I have been working on solvent blends for the last year, on in off, to see if we can make this more forgiving.

All my testing of recent have shown, I have found an answer, so what I did on the last batch about three weeks ago is did a 50% solvent change of what I really wanted to do and watching that batch, I think we have it. Next batch we started to make of activator Friday and will be finished about Wednesday will have the 100% change and should really make this epoxy even more bullet or child proof.

To sum it up, the evaporation rate is changing less then 1%, so no noticeable change there in the application.
Other change you may notice, is in a first coat wet application, any surface contamination or bad air gun adjustment, should not have as a drastic effect on the smoothness and less likely to see a creator or popping issue. Could still happen but it will really need to be abused.

Also the curing over night is much better, even with four wet coats with no flash time, at 72 degrees constant.

Nothing else changes at all.
 
when you induce epoxy do you keep it in a sealed container, or the mixing cup with a strainer/paper towel on top??

just wondering as i have done both but not sure wich is the correct method
 
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