Idiot Proof Finish? No tinting, just protection...

[tbassist4]

Hey everyone,
This is technically about a slab, but I want to use a double bass/violin family finishing technique. It will be an unfinished mahogany body, and I was wondering - what is the easiest and most simple way to put a thin protective finish on wood of this type? I don't want to tint or stain it at all, just add a protective layer. I have limited, but albeit some woodworking experience, and a great deal of patience. I'm hoping the latter will balance out the former, haha. I do plan on practicing on scrap first.

What would you recommend for me?

[LuckyBassPlayer]

If you want it idiot proof, you will probably need to charge the finish with some sort of electricity wires to keep the idiots from touching it

[Jazzdogg]

IME, an "idiot-proof" finish doesn't exist because finishing is ALWAYS a combination of the product being used and the technique used to apply it.

That said, this product comes as close to being idiot-proof as any I've seen:

General Finishes Gel Topcoat - Rockler Woodworking Tools

[tbassist4]

Originally Posted by Jazzdogg

IME, an "idiot-proof" finish doesn't exist because finishing is ALWAYS a combination of the product being used and the technique used to apply it.

That said, this product comes as close to being idiot-proof as any I've seen:

General Finishes Gel Topcoat - Rockler Woodworking Tools

Haha yeah, I'm more just using that as a figure of speech - I just want to find something that I, as a novice, can do without messing up a nice piece of wood.

That urethane stuff looks good, and its extremely cheap too. Can I wipe it on pretty thin? How does this differ from say a polyurethane finish on a production level guitar or bass?

[Turnaround]

There's at least one high-end BG maker that uses this. Nice thin finish, but it will require a bit of maintenance over time. However, the maintenance is easy - clean the finish and wipe on some more.

[tbassist4]

Originally Posted by Turnaround

There's at least one high-end BG maker that uses this. Nice thin finish, but it will require a bit of maintenance over time. However, the maintenance is easy - clean the finish and wipe on some more.

How often? Is this once every several months or once every several years?

[powerbass]

I vote tung oil. I have made several slabs and used this finish, fits the bill with thin and easy to apply. I like the fancy stuff www.sutherlandwelles.com, any tung oil will do.

[Jazzdogg]

Here's a step-by-step tutorial:

Sanded-in Oil Finish

[tbassist4]

Originally Posted by Jazzdogg

Here's a step-by-step tutorial:

Sanded-in Oil Finish

This will work for the urethane as well?

[tstone]

My vote goes to Minwax Wipe-On Polyurethane. Available in gloss or satin.

[George700DL]

Originally Posted by tbassist4

Hey everyone,
This is technically about a slab, but I want to use a double bass/violin family finishing technique. It will be an unfinished mahogany body, and I was wondering - what is the easiest and most simple way to put a thin protective finish on wood of this type? I don't want to tint or stain it at all, just add a protective layer. I have limited, but albeit some woodworking experience, and a great deal of patience. I'm hoping the latter will balance out the former, haha. I do plan on practicing on scrap first.

What would you recommend for me?

Polyurethane. Make it thin by mixing it with mineral spirits 50-50 or whatever you need. A few coats will do it, but give each plenty of time to dry. The can will tell you wait 24 hrs after the final coat, but it actually takes a few weeks to reach it's full hardness. It is a very durable finish.

It will make the wood darker (a yellow tint), so if that is not what you want, go with something else.

George

[Turnaround]

Originally Posted by tbassist4

How often? Is this once every several months or once every several years?

Depends on how much you play, what the bass is exposed to etc. etc. But once a year would probably be more than enough.

[Greg Clinkingbeard]

Originally Posted by tstone

My vote goes to Minwax Wipe-On Polyurethane. Available in gloss or satin.

Great stuff. Apply several coats, let it dry for several days and then rub it out with 0000 steel wool and paste wax.

[uprightben]

t- +1 for poly on your project. If you want something durable you can go with something made for flooring. No matter what you use or how you apply it, as long as you get it on without bubbles, you can usually make it look good with some wet/dry sandpaper and a lot of elbow grease. FYI- violin family instruments are usually finished with spirit or oil based varnish with some kind of sealing "ground" underneath, and this is a very contentous subject. In the guitar world, they usually use nitrocellulose laquer.

[gbaker]

Rub-on finish is the most fool-proof.

But -
If you want some deeper gloss, since it is a BG, spray cans are an alternative. Still easy. Deft gloss in spray cans, available from Lowes, works well and is nitrocellulose laquer, very durable and what the major guitar makers use.

Hang the sanded body (like from a wire hanging from a basement joist) so you can get all around it because you are going to spray at least four coats. Follow the directions on the can. Spray very thin coats, let dry, lightly polish with fine steel wool or a very fine sanding pad between each coat. The drawbacks are the odor and the over-spray. Keep well away from flame.

No matter what finish you use first sand the body well using progressive finer grits - 120, 180, 220, 340, and an optional 400. Don't skip grits or you may see scratches after the finish is applied. To final check your sanding, spray body with alcohol and while wet look for defects. Correct, and then sand once more with your finest grit before applying finish.

Hope this helps, good luck with your project.

[tbassist4]

Originally Posted by tstone

My vote goes to Minwax Wipe-On Polyurethane. Available in gloss or satin.

Originally Posted by George700DL

Polyurethane. Make it thin by mixing it with mineral spirits 50-50 or whatever you need. A few coats will do it, but give each plenty of time to dry. The can will tell you wait 24 hrs after the final coat, but it actually takes a few weeks to reach it's full hardness. It is a very durable finish.

It will make the wood darker (a yellow tint), so if that is not what you want, go with something else.

George

Originally Posted by Jazzdogg

Here's a step-by-step tutorial:

Sanded-in Oil Finish

This seems like a really thorough and excellent finish, but it seems like there's a lot of room for error, even if I'm careful and take my time with things. Sanding might be an issue as I don't intend to fill the grain to begin with. Will this cause a lot of issues with the grooves caused by the grain? It might look a little silly "wet," especially if the grain looks like a bunch of little puddles, haha. I'm still open to a work intensive finish like this, but only if I can correct errors - I don't expect to be perfect even after a few practice runs on scrap.

Originally Posted by gbaker

Rub-on finish is the most fool-proof.

But -
If you want some deeper gloss, since it is a BG, spray cans are an alternative. Still easy. Deft gloss in spray cans, available from Lowes, works well and is nitrocellulose laquer, very durable and what the major guitar makers use.

Hang the sanded body (like from a wire hanging from a basement joist) so you can get all around it because you are going to spray at least four coats. Follow the directions on the can. Spray very thin coats, let dry, lightly polish with fine steel wool or a very fine sanding pad between each coat. The drawbacks are the odor and the over-spray. Keep well away from flame.

No matter what finish you use first sand the body well using progressive finer grits - 120, 180, 220, 340, and an optional 400. Don't skip grits or you may see scratches after the finish is applied. To final check your sanding, spray body with alcohol and while wet look for defects. Correct, and then sand once more with your finest grit before applying finish.

Hope this helps, good luck with your project.

I never considered nitro because I didn't know it was available locally. This seems easier to me and the wipe-on poly since nitro melts into the previous coat, making it much more forgiving on mistakes. I'm actually not looking for a high sheen though, I won't even be filling the wood, as I'd like it to look more or less perfectly natural. I've heard that doing all satin coats will cloud the wood, but I've heard that spraying gloss first and then a final coat of satin will minimize this.

What do you recommend for the most "untouched" look using nitro?

[gbaker]

>>>"I never considered nitro because I didn't know it was available locally. This seems easier to me and the wipe-on poly since nitro melts into the previous coat, making it much more forgiving on mistakes. I'm actually not looking for a high sheen though, I won't even be filling the wood, as I'd like it to look more or less perfectly natural. I've heard that doing all satin coats will cloud the wood, but I've heard that spraying gloss first and then a final coat of satin will minimize this.

What do you recommend for the most "untouched" look using nitro?" <<<

The easy way to cut the gloss is with a final rubbing with 0000 steel wool on all gloss. Satin has a component that "fractures" the gloss and will bleed into adjacent coats, not to say it won't work for you. Test it. Use a test block and experiment with a final satin on at least three layers of gloss to see what you get. And you can see what a final rub with steel wool does for you it the same sequence on the third coat.

Another easy spray can solution is shellac, although it is not as durable as nitro. Personally I get much better results with Deft than polly although poly is also available in spray cans and takes less coats. Deft is almost foolproof if you keep the coats light.

[tstone]

I would dispute the claim that most guitar makers today use nitro lacquer. Gibson is the only large maker I can think of that does. The other major names use catalyzed polyurethane or polyester. The boutique custom luthiers are a different matter, of course.

I've finished guitars with both nitro lacquer and wipe-on poly, and to me, nitro is *way* more demanding, especially if you use rattle cans. If you want a mirror finish, you have to put it on quite thick to build up enough thickness to allow for wet-sanding. Then you have to let it cure for at least a month. Then the wet-sanding and buffing process is very laborious, and it takes great care not to get sand-throughs, expecially on corners and edges. On something the size of a double bass, you're looking at a *lot* of labor.

With wipe-on poly, you apply as many coats as desired -- I'd say three or four is a minimum, because it goes on so thin -- and you're done. I like to apply it with a folded-up piece of lint-free cotton knit cloth. Old T-shirt fabric is ideal. The result is not as gorgeous as a fully buffed-out nitro finish, but it looks fine and is very functional and durable.

jm2¢

[gbaker]

Originally Posted by tstone

I would dispute the claim that most guitar makers today use nitro lacquer. Gibson is the only large maker I can think of that does. The other major names use catalyzed polyurethane or polyester. The boutique custom luthiers are a different matter, of course.

I've finished guitars with both nitro lacquer and wipe-on poly, and to me, nitro is *way* more demanding, especially if you use rattle cans. If you want a mirror finish, you have to put it on quite thick to build up enough thickness to allow for wet-sanding. Then you have to let it cure for at least a month. Then the wet-sanding and buffing process is very laborious, and it takes great care not to get sand-throughs, expecially on corners and edges. On something the size of a double bass, you're looking at a *lot* of labor.

With wipe-on poly, you apply as many coats as desired -- I'd say three or four is a minimum, because it goes on so thin -- and you're done. I like to apply it with a folded-up piece of lint-free cotton knit cloth. Old T-shirt fabric is ideal. The result is not as gorgeous as a fully buffed-out nitro finish, but it looks fine and is very functional and durable.

jm2¢

Glad you cleared up just Gibson uses nitro now, tstone.

tbassist4 is not finishing a double bass, he mentioned it is a BG (slab) in his first post. I would not recommend Deft spray cans for a DB project.

[George700DL]

Originally Posted by gbaker

Rub-on finish is the most fool-proof.

But -
If you want some deeper gloss, since it is a BG, spray cans are an alternative. Still easy. Deft gloss in spray cans, available from Lowes, works well and is nitrocellulose laquer, very durable and what the major guitar makers use.

Hang the sanded body (like from a wire hanging from a basement joist) so you can get all around it because you are going to spray at least four coats. Follow the directions on the can. Spray very thin coats, let dry, lightly polish with fine steel wool or a very fine sanding pad between each coat. The drawbacks are the odor and the over-spray. Keep well away from flame.

No matter what finish you use first sand the body well using progressive finer grits - 120, 180, 220, 340, and an optional 400. Don't skip grits or you may see scratches after the finish is applied. To final check your sanding, spray body with alcohol and while wet look for defects. Correct, and then sand once more with your finest grit before applying finish.

Hope this helps, good luck with your project.

Gary,

Just a side note: why sand in-between coats of lacquer? I thought one of the features of lacquer is to partially dissolve the previous coat, thus adhering to it without the need to sand like you do with poly and other finishes. Is dust the reason?

George