Clearest or "least yellowing" finishes.

younggun · #1 03-16-2013, 08:51 AM

I'm in the beginning planning stages of my first build. I'm trying to cover all my details in the planning stages, and am giving consideration to finish types. I've done a bit of woodworking over the years, furniture and such, and have mostly used a hand rubbed poyurethane finish on most of my products when I need the protection, or natural oil finishes and wax on some things. I don't want to go with a rubbed-on oil for my bass project...looking for something more protective and glossy, but I would like to use a very clear finish. Something that will show the "true" color of the wood without the yellowish tint that oil based poly causes, and that can buff or polish up to a nice shine. Any input from the experts here would be welcome.
Thanks.

T_Bone_TL · #2 03-16-2013, 10:54 AM

I've had excellent long-term water-clear results from polycrylic (a brand of water-based clear acrylic - I suspect modge-poge [more of an art-supply brand] is the same thing more or less) and some water based PUs. Plan on a lot of cure time (weeks, preferably) before buffing if using those. They "dry" fairly quickly but take a lot more time to get "hard."

Hopkins · #3 03-16-2013, 11:19 AM

I dont know what kind of spray equipment you have access to. An automotive urethane clear would be perfect for your needs if you have access to a compressor and spray equipment.

Bruce Johnson · #4 03-16-2013, 02:31 PM

I use Target EM6000, which is a water-based acrylic polyurethane. It's bluish when you spray it on (which is typical of water-based paints), but it's completely clear when dry.

They also make a thicker brush-on version, EM2000vls.

The Varathane Polycrylic is a similar type of paint, very clear and easy to work with. It's available in hardware stores. I prefer the Target, because it's premixed and ready to spray. The Polycrylic is mixed for brushing. You can thin it, but I've found that to be tricky.

Any of these paints can be built up in coats and buffed out to a high gloss.

Quick tips:
The water based paints need to be wet-sanded using mineral oil, not water, as the lubricant. Yes, that's mineral oil, from the drug store, not mineral spirits. I wet sand the Target to 1200 grit.

I've done a lot of experimenting with buffing the water-based paints, and I get the best results using a very soft unsewn cotton buffing wheel at fairly slow speeds. I use Meguiar's #85 and #205 liquid buffing compounds, applied lightly to the paint.

iamlowsound · #5 03-16-2013, 02:33 PM

Bruce: does the Target stuff melt into previous layers like a laquer does?

lowsound

Bruce Johnson · #6 03-16-2013, 03:21 PM

Quote:

Originally Posted by iamlowsound

Bruce: does the Target stuff melt into previous layers like a laquer does?

lowsound

Yes, it does.

Target has their own website and painting forum, including a section just for Luthiers. Dig around on there and it will answer your questions. It's a good company, with good products.

http://www.targetcoatings.com/

younggun · #7 03-16-2013, 06:24 PM

Quote:

Originally Posted by Bruce Johnson

I use Target EM6000, which is a water-based acrylic polyurethane. It's bluish when you spray it on (which is typical of water-based paints), but it's completely clear when dry.

They also make a thicker brush-on version, EM2000vls.

The Varathane Polycrylic is a similar type of paint, very clear and easy to work with. It's available in hardware stores. I prefer the Target, because it's premixed and ready to spray. The Polycrylic is mixed for brushing. You can thin it, but I've found that to be tricky.

Any of these paints can be built up in coats and buffed out to a high gloss.

Quick tips:
The water based paints need to be wet-sanded using mineral oil, not water, as the lubricant. Yes, that's mineral oil, from the drug store, not mineral spirits. I wet sand the Target to 1200 grit.

I've done a lot of experimenting with buffing the water-based paints, and I get the best results using a very soft unsewn cotton buffing wheel at fairly slow speeds. I use Meguiar's #85 and #205 liquid buffing compounds, applied lightly to the paint.

Thanks for the suggestions so far. I've done some spray on finishing in the past, and do have access to spray equipment, but I've always enjoyed and got better results with hand rubbing many (so many I usually loose count) very thin layers of 50/50 thined oil based poly, followed by lots of sanding and buffing. I'm certainly not opposed to spraying, and can set my garage workshop up for it accordingly, but the water based acrylic seems like more my preference if I can thin it and rub it on, as I can leave my garage workspace as is and do it on the bench. I'll definitely look into that option more, and thanks for the suggestions on how to sand and buff it. Gonna head over to their website right now.

T_Bone_TL · #8 03-17-2013, 10:16 AM

As with a lot of things, one secret to doing a good job on your actual build is to try out your process, completely, on scrap/test pieces. While it takes both time and finishing supplies, it increases the odds of success when it matters manyfold.

younggun · #9 03-17-2013, 01:35 PM

Definitely am going to do an entire finish process on scrap before starting on the real thing. I'm a pretty big "plan and practice" before I do, kinda guy. I'm still in the early stages of planning this build, which includes a lot of research, and I also have a couple of other household projects that need finishing before I start this (otherwise my better half would have my head

). Though the finish is the last part of the build, I want to have a good handle on what I'm going to have to do, and plan to do some practicing on scraps pieces before I even start the build. Right now I'm still trying to gather info to create my vision precisely before drawing up a CAD version of what I'm after.
Thanks for the suggestions, and please keep them coming!