Minwax Clear Polyurethane - Need Recommendations

[FatBack]

I just discovered Minwax clear polyUrethane and am very happy with it. I just sanded off the old finish from a junker bass body and sprayed it with the Minwax gloss clear.

I apologize in advance because this is a very basic question, but I can’t find the answer.

If I wanted a solid black color coat under the polyurethane, what kind of paint do I use? I don’t want to end up with bubbling goo by spraying the polyurethane over the wrong kind of paint.

Can I use Minwax poly over:

Acrylic lacquer?
Nitrocellulose lacquer?
Minwax ebony wood stain, stained so much it looks like black paint?

Is there such a thing as polyurethane paint?

I don’t think I’ve ever heard the right answer. Using poly clear for my next refinish is a given - it’s what can go under it that’s the question.

Please let me know your recommendations!

 

[Peegoo]

Minwax is good stuff. Clear polyurethanes are formulated to be applied to bare wood or stained wood surfaces. They may not be compatible with color coats.

It's always best to use a color aerosol and clearcoat of the same brand. What you will find is paint such as acrylic enamels, and right next to them you'll find acrylic clearcoat with the same label. It won't be marked as polyurethane, but it's extremely tough stuff, it self-levels, and it bonds perfectly with the color coat beneath.

I get really great results with Rustoleum 2X aerosols:

https://spraypaint.rustoleum.com/products/gloss-thd/

It is critical that you follow recoat times described on the container, e.g., "recoat between one hour and 24 hours, or after 48 hours..." This prevents wrinkling of the finish. Different brands/formulations all have specific recoat schedules.

Regarding interior/exterior grades: you'd think an exterior-grade finish would be tougher than interior stuff, but that's incorrect. Exterior grades do not cure as hard; that is what allows them to flex a little under temperature extremes and prevent cracking of the finish. Interior grades cure harder because they're not subject to extremes of temperature. They make more durable finishes for solidbodies. Most big-name paint makers offer only "interior/exterior" grade aerosols, and they work fine. But if you can find interior stuff, it's better.

 

[Fretting out]

I’d have no problem putting poly over stain

If you’re gonna do lacquer I’d test it first

I’m thinking it’s gonna have issues of some sort, especially if your lacquer isn’t completely “dry”

 

[EsquireOK]

Poly goes over many things very well. Fender used it over nitrocellulose and acrylic lacquers starting in 1968, and going all the way though the '70s, at least.

However, each product has its own quirks. There is not a universal, specific definition for "polyurethane" across all brands and products, not to mention other types of finish like lacquers. Always test your entire finishing process on scrap before applying it to the actual project. It's common sense.

If all you need is black, I would go for Rustoleum or Krylon acrylic lacquer as my first trial. It's cheap, available on most hardware store shelves, has an excellent spray nozzle, and performs well IME.

 

[FatBack]

Poly goes over many things very well. Fender used it over nitrocellulose and acrylic lacquers starting in 1968, and going all the way though the '70s, at least.

I did not know Fender used poly over nitro. I always thought it was one or the other but I confess I haven’t done much research on the subject.

Minwax gloss poly is a keeper for me so it sounds like some experimentation is in order. Thank you for the info.

Just wondering - if I stained a guitar body over and over with black oil based minwax stain, could it as dark as paint? I believe Stew Mac grain filler can be stained so if I got a flat, grain filled surface and stained it really well, maybe the poly would work ok?

FYI - I’ve had very bad luck with Krylon acrylic on an Explorer-type kit bass I built. I got it polished up ok but it’s the sorriest paint I’ve ever used. Wipe it with a naphtha damp cloth and the paint comes off on the cloth. Rest your arm in one spot too long, the finish melts. Maybe if it were under a coat of poly it’d be fantastic, but I won’t be using the Krylon brand ever again.

 

[EsquireOK]

Sounds like you are experiencing solvent entrapment due to overly thick application. I have used Krylon acrylic lacquers for decades, and they are excellent IME, as are Rustoleum ones.

Lacquers cannot be laid on too thickly, or they will quite literally never dry. The outer shell dries first, leaving solvent mixed in with the underlying lacquer. It has no escape route to the atmosphere at that point.

To get a very hard lacquer finish, you need to use many very thin coats at first. You can get a little thicker as the coats build up, but you can't really "flood" your project with lacquer, or it will always be slightly gummy.

Don't blame the entire brand based on that one experience. I can guarantee you that you can get professional looking results with Krylon acrylics, if they are applied well.

Funny you should mention an Explorer, as I am planning a project right now that will use Krylon Industrial Acryli-Quick Hunter Green on an Explorer.

 

[FatBack]

Sounds like you are experiencing solvent entrapment due to overly thick application. I have used Krylon acrylic lacquers for decades, and they are excellent IME, as are Rustoleum ones.

Lacquers cannot be laid on too thickly, or they will quite literally never dry. The outer shell dries first, leaving solvent mixed in with the underlying lacquer. It has no escape route to the atmosphere at that point.

To get a very hard lacquer finish, you need to use many very thin coats at first. You can get a little thicker as the coats build up, but you can't really "flood" your project with lacquer, or it will always be slightly gummy.

Don't blame the entire brand based on that one experience. I can guarantee you that you can get professional looking results with Krylon acrylics, if they are applied well.

Funny you should mention an Explorer, as I am planning a project right now that will use Krylon Industrial Acryli-Quick Hunter Green on an Explorer.

Good luck with your project. I’ll never use Krylon on a guitar again. Maybe the stuff is good when new. I have no explanation for it coming out of the can in chunks, spitting, or bubbling other than that paint is garbage.

If you can get it to work though, more power to ya!!!

 

[EsquireOK]

Good luck with your project. I’ll never use Krylon on a guitar again. Maybe the stuff is good when new. I have no explanation for it coming out of the can in chunks, spitting, or bubbling other than that paint is garbage.

If you can get it to work though, more power to ya!!!

Are you saying you used an aged can?

Did you shake well before and during use? Did you soak the can in hot water before use and during breaks? Did you spray in ideal weather conditions?

I have never had the poor performance you described from any Krylon or Rustoleum product. The worst I've ever encountered has been ReRanch. Their cans and nozzles are bottom of the barrel junk, even though their lacquer itself is very nice.

 

[FatBack]

Are you saying you used an aged can?

Did you shake well before and during use? Did you soak the can in hot water before use and during breaks? Did you spray in ideal weather conditions?

I have never had the poor performance you described from any Krylon or Rustoleum product. The worst I've ever encountered has been ReRanch. Their cans and nozzles are bottom of the barrel junk, even though their lacquer itself is very nice.

It’s been about a year since I finished the bass so I don’t remember the exact name but I bought a bunch of cans from Ace Hardware that I assumed were new. When I started having so much trouble, I looked up the exact type Krylon paint I’d been using and it appeared to have been discontinued years ago. So, yes, I believe my paint was very old and that may have contributed.

Oh, yes warm cans, spraying in low humidity, made a paint booth, multiple light coats, shake the can for at least 2 minutes (I did 5!), shake and turn can upside down and wipe nozzle while spraying...all that good stuff . The paint came out ok for about 80% of the project. But it would wrinkle the undercoats, come out bubbling, and/or come out in chunks.

The only way I got that thing finished was to break some rules and apply thick coats. When those dried - were talking weeks, I did a lot of sanding and polishing, flaws and all. The paint was dry, not gummy. Hey, I finally got it to look good.

One good thing I can say is that the finish is thin, which is what I wanted. Unfortunately it’s just super polished up bad paint. One day I might get motivated and sand it all off and redo it.

I really wouldn’t use Krylon on anything other than the wife’s flower baskets or the kids’ pinewood derby cars. I don’t think it’s made to go on something high quality like a guitar.

 

[FatBack]

I might try Rustoleum gloss black acrylic under a coat of Minwax gloss poly.

I’ll try it out on a 2x4 and if it works, that’ll be my new “recipe” for a gloss black finish. Thanks for the input, everybody.

 

[Mr. Neutron]

Just wondering - if I stained a guitar body over and over with black oil based minwax stain, could it as dark as paint?

In an effort to get a dark black Roasted Swamp Ash body, I once dyed that body with some of Behlen's Jet Black NGR Solar Lux dye. Put on 2 coats of this, and it still was kind of a dark brown; not really black. Nowhere near as dark as paint would get it.

So, I next put on some MinWax Ebony oil-base stain on it. It got a little bit darker, but still wasn't quite there yet. I next mixed some cheap Zinsser Bullseye shellac with some blue Transtint dye and brushed/rubbed that on. I probably could've mixed this blue in with Solar Lux Jet Black, but didn't for some reason. Anyway, this got me the dark black I was going for. I finished it with the exact same MinWax Poly from an aerosol can that you showed in the pic above. All these finish "components" worked well together with no probs. I let the body dry for a coupla weeks, then wet sanded and buffed it.

Now, I was wanting a "ceruse"/contrasting grain type of finish on that body. Where it went wrong for me was when I did the grain filling and sanding, which you can see in the pics. My grain fill kinda "bled" into the main black coloring. It did eventually get "fixed", but for just a black body, this worked good for me......





This would probably be a good argument for practicing on some test pieces of scrap beforehand. I used this guitar to learn on, rather than scrap. It worked out for me this time, but would've been worth the extra time and effort to "practice' and do my scientific research on some other lumber first.

Added in EDIT:

Yes, there is polyurethane paint, but it's pretty spendy for just a guitar body, and it's usually a 2 part paint that gets applied with a spray gun. I don't have any pics of my kinda dark metallic blue guitar, but I bought a can of paint from a local auto parts store with a paint dept.. You can give them a paint code from a car with the color you like, and they can make you an aerosol can with that color. You shoot some primer on (Rustoleum has some aerosol stuff I've had good luck with). You spray the mixed color on, wait 15 minutes, and then shoot it with SprayMax 2K "Glamourcoat" rattle can clear 2K poly. You can get this poly from Amazon, and in satin or gloss, or at the place where I get my paint (Advance Auto Parts in Sandy, OR. This stuff dries really fast. I believe you can wet sand and buff in a day. Do wear a good respirator with the charcoal filters when shooting all this, or even the poly you showed. This paint and 2K poly has some nasty stuff in it.

I also hope that you know that for a glossy black paint job, your sanding and prep must be perfect......

 

[Mr. Neutron]

https://images-na.ssl-images-amazon.com/images/I/81RqsWPi2iL._AC_SL1500_.jpg

Here's the 2 part "can-inside-a-can" poly. Follow the directions to a "T" with this stuff. It has a shelf life, so get as fresh a can as possible. For that reason, I'd recommend buying local if possible, rather than thru ebay or amazon, where likely you won't know the date.

 

[Leonardocoate]

I have used Minwax black accelerator which gives a chard look and then I sanded to give it a worn look in some spots. I used a satin poly (Minwax)as a top coat...turned out pretty sharp. I will try to add a picture later

 

[Dacious]

I just discovered wipe on poly. Minwax makes this. It works well. In warm weather you can put coats on every 3-4 hours. Let it go tack-free.

After 3-4 days you can take it down with 1000-2000 grit and buff it. I'm using the local Australian equivalent made by Feast Watson. It's poly diluted by thinners.

Amsterdam acrylic water based ink dyes.5 coats in.