The finish on my Ataman red white and blue laminate stock has yellowed and the wood looks faded. I can sand it and the colors pop again. What finish is recommended to best display and preserve the colors on my stock. Gloss is fine as it is not a hunting gun. I am not sure what the factory finish was, but looks like possibly polyurethane?
Spar urethane is the go-to exterior urethane for dealing with UV, but it DOES turn yellow, and your red-white-blue will turn orange-public toilet-green. Most (all that I'm aware of) urethanes yellow, it's what they do, but it goes un-noticed over wood-colored wood. A notable exception is old pine furniture, pretty sure you can guess the age of pine furniture by gauging the degree of yellowing!
Don't do it!
Think about polyurethane... what's made from it? Couch cushions... yes, that yellow!
I'm a fan of epoxy, if not least for the lack of odor. It is quite plasticy, has different feel when sanding and buffing, not always predictable when thinned, and is often too thick to spray.
For this reason, I've settled on automotive clear. It lays flat, resists UV, sands and buffs nice as you please.
An added bonus, unmixed clear has more shelf life than most purchasers.
Bill Rabbitt and Steve English have been doing a little experimenting with finishes on laminates. They have used Modern Masters DP401 Exterior Dead Flat Varnish Low VOC as a base coat to help keep the colors from darkening and loosing their vibrancy. I think 3 to 4 coats before applying top coats with UV protectant. They happen to use spar varnish over top. Now will this keep it from eventually yellowing, I do not know but it seemed to help initially keep the colors more true.
Here's a sample board with best results shown only using 2 coats of the Modern Masters Varnish.
Jeff P
Modern Masters DP401 Exterior Dead Flat Varnish Low VOC as a base coat
That would be what's called "water based polyurethane" https://thecraftsmanblog.com/should-i-use-water-based-polyurethane/
"Water-based polyurethane is technically a misnomer since polyurethanes are an oil-based product. Water-based polys use an acrylic resin just like water-based paints. "
https://en.wikipedia.org/wiki/Acrylate_polymer
Oil based polyurethanes, such as spar urethane, still turn white base coat to piss yellow. Based on the OP, I'd say you're not in favor of yellowing, and I'm tossing it back out there. I do use polyurethane (oil base) over wood-colored wood, sometimes, because the yellow is what you expect to see, but I might also spray clear if it's an easy part.
No offense to people who say "Polyurethane is the bee's knees!", they can use it, I use automotive clear, because it's CLEAR and maintaining the color coat is the whole point!!! JMHO... and acrylic might be just the thing, can't say, I don't use it, unless matching existing finish.
Thanks to JeffP for bringing up acrylic.
Let me edit to rephrase that...
![20200115 172648[1]](https://airgunwarriors.com/wp-content/uploads/wpforo/attachments/1473/16640-202001151726481.jpg "20200115 172648[1]")
![20200115 172716[1]](https://airgunwarriors.com/wp-content/uploads/wpforo/attachments/1473/16641-202001151727161.jpg "20200115 172716[1]")
After spending so much time working to match this Ironman bike we did (came back crasht) if I were stupid enough to spray a coat of piss yellow over it and screw up all the colors, I should punch myself in the face, I should call the customer and have them drive out to punch me in the face, and maybe give Wifey and the kid a free shot while the gettin's good.
Even spraying umpteen base coats to match factory paint sometimes (plus the $150/pint factory color, you don't even wanna know) the idea of putting yellow on top makes me want to drop my pantelones, pepperspray myself in the anus, light my hair on fire, flail my arms widely and do a running faceplant in a pile of broken glass, then finish using the can of pepperspray to extinguish my smouldering scalp.
Yesterday I was gonna point out the purple $10 Harbor Freight gravity fed HVLP guns as acceptable for spraying clear, but was hesitant, and couldn't remember why. Now I remember... that purple color is not anodize, it's actually purple tinted clear paint over the aluminum.
I do still use them as a primer gun for DTM epoxy primer on low value items like steel (because it matter AS MUCH if you've got goobers in your seal coat) but they are nigh impossible to clean adequately for switching colors.
If you only spray clear, primer, or one color, AND clean the gun right away, they work pretty OK. Just don't soak the body unless you want to spend $40 worth of time cleaning a $10 gun!
After thinking some more, there is a product for musical instruments commonly sold as "Guitar Lacquer" which SHOULD be nitrocellulose based.
Not "safe", not the easiest to work with (definitely a different feel from low VOC clear) works better on oily woods over a specific sealer, maybe not an issue here, and it's NOT UV resistant. Yes, you can take it outside, but don't leave it outside.
Very shiney, excellent clarity and wetness, buffs OK, mostly went extinct in the early-mid 1900s, due to better finish chemistries. I've only sprayed a pint of it, ever, and not an expert
You can get it in the (hated) rattle can whose valve will invariably clog and waste any unused product, a deal clincher for so many! The solids content is 20% or less (more coats to build) the rest is solvent.
There is a specific thinner for lacquer, ironically named "Lacquer Thinner" which also makes great gun cleaner, but between the 3 components we're now up to $50-75, and I don't REALLY see any specific advantages except authenticity.
https://www.amazon.com/Mohawk-Stringed-Instrument-Lacquer-13/dp/B07V6KV71L/ref=sr_1_3
https://www.amazon.com/Mohawk-Finishing-Classic-Instrument-M610-1406/dp/B07PG9Z64V/ref=sr_1_2
https://www.amazon.com/dp/B07Y26PG9C/ref=dp_cerb_3
$67 delivered is so cheap for 1 1/4 gal of clear. Since there is no color coat (base) no need to worry about compatibility, just wash your part with some cleaner. Medium activator is right for this time of year. Thin with xylene or lacquer thinner, acetone is faster but likes to absorb water, I prefer not to risk using old acetone but a fresh can is OK. "Paint Thinner" is 100% no-go, too slow.
Don't let any activated material get back into the gallon, it'll all go off.
I'm not trying to be pushy, just helpful. A lot of people... well... when you know something from experience, it's easy to tell people "Oh ya! Just do this and that and this!" but so often (like when I was young) the folks have no basis of knowledge to work from and all they hear is "Blah blah lacquer blah spray" and you've been zero help to them whatsoever. Zero.
I always liked schooner varnish myself, specifically designed for UV protection on wooden boats. Interlux works well, can thin it easy enough with Xylene (or their overpriced 97.5% xylene mix thinner) to use with a spray gun or just roll/brush it on. It is slower to dry than many finishes, but it will be a good hard durable finish that wears like iron. Good high gloss results you can get with it too.
On many applications a nice warm tone is desirable. It may be that my gun finish would have faded UV or not as the amount of time in the sun is not that great. GWH I think I will try spraying the clear. It is a small stock and not that difficult to sand. Thanks for sharing your experience, that is why I asked. I have finished many stocks, but they were usually walnut and warm tone was fine in that application.
I've done a few stocks with various wipe on finishes. I would like to eventually try spraying one. Can you recommend a simple spray booth setup? I've seen people make them out of pvc tubing and plastic. What does deter me is the exhaust fan set up and the potential for explosion using a non explosion-proof fan motor with oil based finishes. Can you provide some insight?
Thanks
Jeff P
I would like to eventually try spraying one. Can you recommend a simple spray booth setup?
Most fan motors are induction, there are no sparks, and I would worry 0% about igniting vapors. I've tried igniting vapors as an explosive mixture, and other than pure dumb luck, it's not easy to get the proper fuel/air ratio. You WILL get a lot of crap stuck to the fan blades, keep that in mind.
Your fan needs to pull, not push, like a welder using a fan to draw smoke away, not blowing the smoke (and your shielding gas) away.
A booth? Meh... if there aren't leaves falling, or dirt blowing, you're OK. Something as simple as a carport would be fine, direct the fan away from stuff you want to still like.
In my experience, most of the trash that gets in your spray, is trash you've blown up yourself. Blow the stock out completely, and wash it with cleaner. Same goes for kicking up dust, we spay the floor to keep the dust down, but we also have a lot of overspray and sanding dust. Just be aware of the concept.
This is most of where the fan comes in, that same overspray that just got on your old lady's car, will land in you spray. Aim for airflow speed around 1ft every 1-2 seconds, or kinda like the speed you'd see people doing Tai Chi. Not fast, just a slow drift away. Honestly, given that we're not dealing with footage of horizontal surface, the chance of overspray landing back on your work is not too bad, and if you're outside, you probably won't fall out from fumes.
Humidity effects dry time, and right after a rain the air is clean (free of dust) but it might also be too wet. I'm not sure how to define the sweet spot, and all my paint work has been done in FL, so we probably have different conditions. Not sure how to spell this part out, but dead still air has a lot less trash in it.
Dry air might be the biggest challenge. I've always been amazed at the level of oil contamination which catalyzed urethanes endure, but water not so much. If you get fish eyes, it's either water or another contaminant. I would usually wash the uncured clear off right away, EVEN IF it does cure, the fish eyes might be so deep that you'd have to sand back to zero to remove them. Then, you'd still have some contaminants to deal with, better to wash it off with xylene, ect. Throw some in the gun (because it needs cleaned now too) and tighten the pattern up, blast it right off while it still wants to run!
Some people make everything into an exercise in spending money, I don't encourage that, not for one job. We paint show bikes (or for pepole with more money than they know what to do with) and it's a little different (don't be me!)
The simplest thing is to get a "toilet paper filter" like the Motorguard, easiest way is to get the 1/4 NPT and just run it inline on the hose. These also work very well for plasma, when combined with a coalescing filter (regular water trap) If I were trying to be cheap, I'd run my regular everything, with that Motoguard at the end of my regular hose, then downsteam of the Motoguard I'd put a clean whip, like one of the cheap 10ft scrap rubber hoses from HFT. They are kinda expensive for one job, but it's a lifetime purchase, and consumables are basically zero since the filter can be set out to dry, or washed in denat, etc.
For me? My compressor is an 80 gal with oil lubed pump, the air system features a 20 gal tank (stored in the ceiling) fed from the bottom, with air exiting the top. When the big compressor stops running any water in this tank runs back down and I have near zero water in my downstream water trap. Usually zero. This is, IMHO, a brilliant use of a junk compressor, as a expansion tank which also increases capacity. Then water trap, then Motoguard, then a restriction style reg at the gun, a dessicant widget, and I only spray through a hose which has never had water or oil in it. But, I'm anal, and so long as your hose isn't sloughing trash, you're probably OK. OTOH, time is expensive and clean hose is cheap.
The reg is usually set at 40psi, you could run lower, but I like it around there depending on the spray-ability, and hose restrictions.
Personally, I would hang the stock vertical, so that any runs (not saying I get runs, but you might) are easier to sand off the flat, instead of running round the radius.
Get a 2x4 and practice getting the paint to ALMOST run, but not quite. Ice cream paint job! This part about FFing with the gun on some practice media is important, and frequently overlooked. It'll save you a lot of headache when it's time to spray the work.
Spray a dusty coat, from far back, don't wet it out, and give it 2-5 mins to dry. This is your "tack coat" and provides a more even lay-down of the second coat.
Successive coats should go on before the stock dries, read the instructions, or stay inside 20 mins. If your clear isn't cured enough at 20 mins to throw another coat on, something is wrong (hardener speed and your specific temp?) stop and reassess. If you go outside the recoat window specified on the label, you will have to scuff it, which might mean waiting a much longer time for it to cure up before touching it with paper. In other words, wasting an hour might actually be a waste of many hours.
check the timestamp on this post, it could probably be more coherent, but WTF it's early AM and you know... let me know if something isn't clear, or you disagree, or thing I'm a dum-dum, or whatever... I was a really crappy painter before I was a decent painter, and still have a lot to learn.
The West System Epoxy finishes are resistant to DEET found in insect spray cans. Theoben used epoxy for their stocks.
Fine Woodworking did a article that rated finishes protective qualities for vapor and liquid. Epoxy was the best.
There's even a dude that makes wooden cowboy hats that he impregnates and finishes with the West System. Hat size remains the same.
