Pore-filling around bridge mask?

[joeguam]

Hello Everyone,

I'm very new and starting my first build, but this will be the 3rd time finishing (or refinishing) an instrument. I'm in the process of planning out my build and have one question:

How do you pore-fill/level-sand with the bridge tape-mask on the top?

I have followed this exact process to great success with my first two pore-fills using Z-Poxy: https://www.youtube.com/watch?v=gc5hN3gTONM

I plan to use z-poxy again to fill the pores in the solid mahogany I'll be using. I want to mask off the bridge footprint to make it easier to apply the finish evenly, but I just have this feeling that it will rip right off when I level sand the z-poxy.

Do I pore-fill over the bridge area, sand to bare wood, then mask the bridge area?

Do I mask the bridge area and just be careful to sand around the tape-mask?

Please help!

Thanks so much!

...

Joe

[Jeff Highland]

I have only finished one mahogany top(and a couple of other hardwood tops) but I just pore filled, sanded and finished  and polished the whole suface.

Then I positioned and pinned the bridge, scribed the outline and scraped the footprint down to wood for gluing,

Basically the same as I do for a spruce top, but with pore fill added to the process.

If you really want to mask, and many prefer it, I'd do it after pore filling and sanding

[jbbancroft]

Before removing the masking tape, cut around the edge of the tape with a sharp exacto knife, or similar sharp knife.

Jim

[joeguam]

So if I understand correctly, it's okay to glue a bridge to a surface that has been pore-filled and sanded back to bare wood?

Or, should the bridge footprint not be pore filled at all?

I'll be finishing with truoil so masking the bridge footprint won't be a problem. The issue I see is the vigorous sanding needed to pore fill with z-poxy...it'll rip the bridge footprint mask right off.

[Jeff Highland]

Yes it's Ok IMHO

[joeguam]

Thanks Jeff, this will make things a lot easier. I'll pore fill, sand back down to bare wood, mask the bridge footprint...then apply truoil.

Appreciate the help!

[Paul Verticchio]

"..then apply truoil."

Are you going to finish the top in tru oil?  It's your build, but if you do that, you'll likely have some serious humidity related issues and possible stability issues with the instrument.

Also, oil and glues don't play well together.

My comments are only cautionary and food for consideration.

Best of luck with your build & have fun with it :)

[Jeff Highland]

I finished my first couple of instruments in tru oil

No humidity issues or stability issues

It is more like a varnish than an oil and does not penetrate deeply

Yes you need to get to bare wood before gluing

[joeguam]

Thanks Paul, I'm very interested in your cautions. I've seen very many successful finishes with TruOil online, even on the top. There are some great examples I've seen of bringing TruOil to high gloss with lots of very thin coats and the articles I've read claim TruOil is much more durable than French Polishing as it is a varnish that hardens, unlike natural oils (e.g. tung, lemon, etc.). Traditionally, TruOil is used on gun stocks which are subjected to much more harsh environments than instruments. TruOil also claims that their product is actually a protectant against humidity extremes, and also helps to prevents water damage.

I truly respect your knowledge so please share any advice you can based on your experiences with TruOil. All that I know is what I've read from others who have blogged their experiences. I used minwax wipe-on polyurethane for my two previous refinishing jobs, but that's only because that's what I could find locally.

Thanks in advance!

[Paul Verticchio]

Thanks Joe :)

Your answer makes perfect sense to me. I withdraw my caution.

I'm only familiar with it for it's original purpose after a brief and aborted foray into gunsmithing years ago. I am such a mechanical geek. I agree that it builds to a very beautiful & durable sheen. And, it's soooooo easy to use and easy to control the final results.

We all learn and get educated by each other and you just contributed invaluably to my databank.

Have fun with your build and thanks again for the info. Sounds like it's gonna be a good time for ya :)

[joeguam]

Thanks so much for your reply Paul, I really appreciate it as my confidence is restored again in TruOil. :)

I've only posted a couple of times here on Frets.net, but I've read many threads and posts. I do remember your name specifically from my previous threads and other posts. Once again, I respect your knowledge and thank you very much for taking the time to provide some info to help me.

Cheers!

[sylvan]

Glue will not stick well to any finish. It needs to be clean. In acoustic guitars the best masking of the bridge area I have found is with Frisket (1 mil) tape. It is used in the airbrush industry and sticks very well. Do a google search. Once I have masked off the bridge area I can paint, sand AND buff the guitar without removing the frisket tape. The, using the bridge I carefully cut the finish around the bridge and remove the Frisket tape. Now you have an exact footprint of your bridge area and, IT IS CLEAN! Ready for glue!

[joeguam]

Thanks Sylvan! So you're recommendation is to use Frisket even BEFORE I lay any z-poxy down to pore fill?

Or, should I pore fill first, the lay down the Frisket?