Help with OSMO PolyX

[Bob_H]

Hi - I am looking for advice from anyone who has experience in using OSMO PolyX as a guitar finish. I am hoping to use this as a finish on two mandolins I am working on.

In particular, I would appreciate advice on:

1. Surface preparation: how far should I go prior to applying OSMO - is sanding through to 320 enough?
2. Pore filling: is poor filling desirable under OSMO? Will it contribute to uneven absorption of the OSMO? If pore filling is desirable, what would work best with OSMO?
3. Suggestions on application: OSMO's advice is to adopt pretty simple application regime - wipe on, wipe off, repeat, buff. Any further suggestions? Any benefits in applying additional coats (as with Tru Oil)?
4. Buffing / Polishing: I've read of people applying various polishes over the top of OSMO, and perhaps a light hand buffing. Any suggestions here?

I asked for advice in an earlier post, but realise now that I had buried the request for advice low down in the post. So I thought it better to be direct!

[kiwigeo]

https://www.acousticguitarforum.com/for ... p?t=626670

[Bob_H]

https://www.acousticguitarforum.com/for ... p?t=626670

Thanks Martin - there are couple of threads on that site that discuss Osmo as a finish, with plenty of variety in methodology and desireable use. Not a lot of consensus though: some people pore fill, others say it ruins the finish; some do two coats and say more are pointless because of chemical bonding limitations, others advocate 10 - 20 coats. However, I know a few people are using it professionally as a preferred non-gloss finish (eg http://jensploesserguitars.com.au/), and I did see a very nice Osmo finished guitar at an ANZLF dinner in Canberra a few years back, so I was hoping I might get a steer from someone with recent experience!

Anyway, I'll have a crack anyway, and see how I go

[Bob_H]

I have applied 3011 Polyx Oil Gloss to my current mandolin build. I have kept it very simple, inline with the official advice on general application:

1. Prepare surface, filling gaps etc. as usual. Sand through to 400 grit.
2. Thorough clean, dampen to raise the grain, sand at 400 grit.
3. No pore filling or sealing. Shellac had been used to seal binding channels etc during the build but this was largely removed during sanding.
4. Apply with a lint free cloth, rubbing firmly to achieve an even coverage and then thoroughly wipe off excess. Leave to dry (18- 24 hours).
5. Lightly sand with 400 if required. Repeat as desired.

I have applied three coats so far, and I am pretty happy with the finish - a very warm, subtle finish. It feels very nice to handle. I may apply another coat or two to see if it adds anything.

[Mark McLean]

Bob's result looks pretty good!
I have also used Osmo hard wax oils on a couple of instruments. Method was much the same as Bob. Initial sanding through the grits to 400. I was using it on Blackwood and I did not pore-fill. I applied by hand with a pad (I use Swisspers brand makeup removal pads that you can buy in the supermarket) and then wipe off with a cotton cloth. Very simple. I applied three coats with about 24 hours between them. You are not trying to build coats - just looking for a nice lustre and a protective coating. It is different from Tru Oil where people often build up to 20+ coats for a gloss finish. The result with 3-4 coats of hard wax oil is a hard wearing satin finish with a natural timber look. If you want a smooth pane-of-glass lacquer type of finish this is not the right product - but I really like this style of finishing. Another great thing about it is that it is completely repairable. You can sand part of it back to bare wood and then reapply a new oil finish and it will blend right in. You can also apply it over shellac or over stains such as a hand-rubbed burst.

[Bob_H]

Thanks Mark

[colin north]

I've done a guitar neck, back and side using PolyX 3043 (silk), following this advice [youtube]https://www.youtube.com/watch?v=GzNxw4zmZuc[/youtube]
No pore fill, the thin stuff first, then the PolyX, 4 coats.