Finishing Experiments

Questions and answers for beginners. If you have a question, so do most other people.
scamp
Posts: 223
Joined: Sat Mar 26, 2022 8:19 pm

Re: Finishing Experiments

Post by scamp »

Great input/suggestions
It's helped a lot

Taking in all I've learned here is my plan of attack...

1) Sand everything down to 220 with the grain except the front which is sanded with 220 against the grain
2) Mask the bridge location and fret board with tape
3) Make a batch of #1 non-waxed shellac using flakes and high grade Denatured Alcohol (190 proof)
4) Wipe everything down with Naphtha
5) Apply shellac to back and sides to start pore filling process and let dry
6) Apply Aqua Coat pore filler using a cotton mouse with small rotating strokes and then quickly wipe off excess
7) Let dry and sand lightly ( so a not to go through filled pores) with 220 grit
8) Clean off surfaces with Naphtha and tack cloth
7) Repeat as necessary ( probably 4 times total )
8) Apply coat of shellac
9) Lightly sand with 320 grit and clean off with Naphtha and tack cloth
10) Start applying Tru Oil in a mix with mineral spirits ( 3 parts Tru Oil with 2 parts mineral spirits )
11) Let dry and then scuff up with 0000 steal wool and then clean off with tack cloth
12) Repeat 14 or so times ( as necessary )

Note... I will be doing the body and neck separately and then bolting them back together when done. I wasn't planning on shellacking the top of the guitar ( spruce) before applying the Tru Oil as I don't think it's necessary from what I have seen on line.

This is the plan. Let me know if you see anything wrong with it

Thanks
Kevin Sjostrand
Posts: 3712
Joined: Sat Feb 09, 2008 8:06 pm
Location: Visalia, CA

Re: Finishing Experiments

Post by Kevin Sjostrand »

I can suggest if you haven't yet purchased the shellac flakes, if you have Zinnzers "Seal Coat" in your local hardware store, it is only shellac cut with alcohol to a 2lb cut and will work as well as dissolving the flakes. At about
$15 a quart with long shelf life I find it a better alternative. I use it for French polishing too. I've done the flake thing and found no comparable difference. Seal Coat has no wax. The cans marked Shellac is waxed...you don't want that. If you want to cut it further (thin) add denatured alcohol or the distilled stuff if you can get it, as you've indicated you can.
Just what I do and my suggestion.

Kevin
scamp
Posts: 223
Joined: Sat Mar 26, 2022 8:19 pm

Re: Finishing Experiments

Post by scamp »

Is this the stuff your talking about

https://www.amazon.com/Rust-Oleum-Zinss ... B000C02BXW
Diane Kauffmds
Posts: 3246
Joined: Sun Mar 09, 2014 8:13 pm

Re: Finishing Experiments

Post by Diane Kauffmds »

scamp wrote: Sun May 15, 2022 12:20 pm Is this the stuff your talking about

https://www.amazon.com/Rust-Oleum-Zinss ... B000C02BXW
Yes. That'll work perfectly. It's just predissolved dewaxed shellac.
Diane Kauffmann
Country Roads Guitars
countryroadsguitars@gmail.com
Diane Kauffmds
Posts: 3246
Joined: Sun Mar 09, 2014 8:13 pm

Re: Finishing Experiments

Post by Diane Kauffmds »

scamp wrote: Sun May 15, 2022 9:42 am Great input/suggestions
It's helped a lot

Taking in all I've learned here is my plan of attack...

1) Sand everything down to 220 with the grain except the front which is sanded with 220 against the grain
2) Mask the bridge location and fret board with tape
3) Make a batch of #1 non-waxed shellac using flakes and high grade Denatured Alcohol (190 proof)
4) Wipe everything down with Naphtha
5) Apply shellac to back and sides to start pore filling process and let dry
6) Apply Aqua Coat pore filler using a cotton mouse with small rotating strokes and then quickly wipe off excess
7) Let dry and sand lightly ( so a not to go through filled pores) with 220 grit
8) Clean off surfaces with Naphtha and tack cloth
7) Repeat as necessary ( probably 4 times total )
8) Apply coat of shellac
9) Lightly sand with 320 grit and clean off with Naphtha and tack cloth
10) Start applying Tru Oil in a mix with mineral spirits ( 3 parts Tru Oil with 2 parts mineral spirits )
11) Let dry and then scuff up with 0000 steal wool and then clean off with tack cloth
12) Repeat 14 or so times ( as necessary )

Note... I will be doing the body and neck separately and then bolting them back together when done. I wasn't planning on shellacking the top of the guitar ( spruce) before applying the Tru Oil as I don't think it's necessary from what I have seen on line.

This is the plan. Let me know if you see anything wrong with it

Thanks
Your list looks good.

Always sand wood with the grain, including the top. When it comes to finish, you don't necessarily have to go with the grain if you're using micromesh to further polish the finish.

You can apply the Aquacoat using a cotton pad if you wish. You can also use a paper towel or any cloth. Just use a small amount and work into the pores. I just use 1/2 of a paper towel, then throw it away. That way, I'm using something very clean with each subsequent coat.
Diane Kauffmann
Country Roads Guitars
countryroadsguitars@gmail.com
sjhouska
Posts: 19
Joined: Thu Feb 24, 2022 1:09 pm

Re: Finishing Experiments

Post by sjhouska »

Trying to not reinvent the wheel or repeat previous posts in this thread, but I have a few questions about my upcoming efforts to finish my first ever kit build . . .

1) When using LMI's clear Aqua Coat on my East Indian rosewood back/sides and headstock veneer, how do I remove the saw dust after I sand between coats of Aqua Coat (I guess the same question for all sanding between coats during the finishing process)? I saw a vid link via the LMI site regarding applying Aqua Coat, and the fellow there used an air hose to blow the sanded Aqua Coat dust off. I don't have a compressor. Is there some economical, easy way to remove the sanded dust (e.g. tack cloth)?

2) this was covered previously in this thread but, to be sure, I can use Minwax wipe on polyurethane after using Zinsser shellac as a sealant, right? The directions on the Zinsser can say to NOT use Zinsser shellac under polyurethane but, rather, to use Bulls Eye SealCoat. Apparently, both Zinseer is also a "Bulls eye" product. instead of Zinzer shellac.

3) What is the Naptha used for? Is it a necessary step?

$) As someone looking for an easy-to-apply finish, at this point I am planning to use Minwax wipe on poly instead of Truoil, based upon something I read to the effect that Tru Oil is very thin. I therefore somehow assume (with all the attendant risks/consequences of making an assumption) that Minwax might be "thicker" and therefore offer more protection than Tru Oil. I will likely do 4 coats of the Minwax wipe on poly, and could easily do 4 of Tru Oil. Any input regarding my logic or lack thereof, or which direction I should go (Minwax wipe on poly v. Tru Oil, or some other product), will be greatly appreciated.

6) I believe that my neck is mahogany, brown in color (maybe even reddish?) but much lighter than the rosewood back and sides. I am thinking of staining the neck (but not the headstock which has a rosewood veneer) with a Minwax walnut stain before sealing, pore filling, etc. thoughts?

Thank you.
Stray Feathers
Posts: 677
Joined: Sun Sep 08, 2013 11:39 pm
Location: Ladysmith, BC

Re: Finishing Experiments

Post by Stray Feathers »

Compressed air is a help but not essential. Dust after you sand with a cloth or fine brush. Then use a tack cloth (commercially available) which picks up more dust. Naphtha is useful to wipe the surface to pick up any residual dust, and it dries off quickly. If you can't find naphtha, Coleman stove fuel is pretty much the same.

I've only used one water based finish and I used the companion sealer with it. If the manufacturer says to not do something, I would be careful with it. As for finish, I have not used Tru-oil yet but it is widely recommended for instruments. I think any wipe-on finish will be almost the same thickness in the end. And my own personal opinion is not to stain necks. If you wipe the neck with naphtha it will let you see more like what it will look like with a finish on it. I have a Larrivée rosewood guitar, and also one that I made, with mahogany necks and they look great. Bruce W.
Kevin Sjostrand
Posts: 3712
Joined: Sat Feb 09, 2008 8:06 pm
Location: Visalia, CA

Re: Finishing Experiments

Post by Kevin Sjostrand »

You want to use Zinnser "Seal Coat", not the can labeled "Shellac".
I know it's confusing but the SHELLAC has wax. That's why you wouldn't use it under another finish.
The "Seal Coat" is de-waxed shellac cut with alcohol.
That's what you want. It can even be used as your finish for French Polishing. I have done 2 guitars using it for French Polish with from what I could tell as good as the results I got on two guitars using flakes.
Don't use alcohol to wipe down the Seal Coat. You will dissolve it. If you want to thin the Seal Coat, use denatured alcohol.
Diane Kauffmds
Posts: 3246
Joined: Sun Mar 09, 2014 8:13 pm

Re: Finishing Experiments

Post by Diane Kauffmds »

Use Naptha to wipe any finish, or bare wood down. It won't react with anything and it won't raise the grain. I use it daily on all guitars.

First, make sure any shellac used is dewaxed. You don't want wax. Seal the bare wood with the dewaxed shellac.

Second, pore fill, using Aquacoat, or your choice of pore filler. MAKE ABSOLUTELY SURE IT IS THOROUGHLY DRY BEFORE SANDING!. Otherwise it'll leave white stuff in the pores. Use it sparingly. It'll dry quickly, depending on your humidity level. I use a paper towel to spread a small amount on. After dry, lightly sand with 220g. Repeat as often as necessary, until you see that most pores are filled.

Third, apply the finish of your choice. Aquacoat and shellac work well under oil or water based finishes. I've used hand applied polyurethane. It works just fine and makes a nice finish. TruOil is also a.good choice.
Diane Kauffmann
Country Roads Guitars
countryroadsguitars@gmail.com
Danl8
Posts: 733
Joined: Mon Jul 28, 2014 7:50 am
Location: Chadds Ford, PA

Re: Finishing Experiments

Post by Danl8 »

Diane, Kevin and Bruce offer excellent advice. Follow it and you will be way ahead of the game. I will add that fresh tru-oil in frequent thin rubbed coats will result in a very nice finish. Although I use nitro more, tru-oil has not disappointed.
Post Reply