First time finisher- oil and sanding sealer disaster!

[pauli]

Hi all,

I've found this forum after searching around a bit about finishing techniques and products, and was hoping some folk in the know might be able to offer some advice!

I've almost finished a course building an acoustic guitar, almost finished i say - in that i've not Finished it yet. The standard process in the course was a Danish oil rubbed on finished (Rustin's), with no sealer or undercoat, etc, just 6 or so coats of the oil. I was interested in trying to fill the open grain on my guitar (it's east indian rosewood back and sides and mahogany neck), so I tried this Feast and Watson Sanding Sealer stuff. So far so good, brushed on the sanding sealer, and the woods went a bit darker, and generally, it all looked pretty nice.. Not particularly even though, of course. So the instructor sent me home with oil and instructions to sanding the sealer level then oil.

I've started rubbing it back with wet and dry silicone carbide 400 paper, my plan to work through 400 wet, then 600, 800 and 1200 before starting with the oil. This might be ridiculous, i honestly don't know... but I've started down this path, and its gone horribly, first there was shiny spots and matt spots, then lots of white little streaks, which i imagine to be the pores of the rosewood. The sandpaper being wet, isn't clogging, and is rubbing very easy and I can't feel much friction, but now a good deal of the wood is very pale and whiteish, and i think the pores might be open again.. to make things worse, each rub with the sandpaper is now producing a grey muddy substance which I'm wiping off with a cloth..

The intention was to get a nice level darkish finish, and somehow get a nice gloss (i know oil isn't the best for this, but i don't have equipment or knowledge for either lacquer or french polish). Can anyone help please! :-) I'm also looking for suggestions on another oil to get a higher gloss ( the Rustin's danish oil claims to be low lustre.. i'm assuming this is low gloss??).

cheers and thanks for reading,
Paul..:confused:

[ubeaut]

Stop sanding. Let it dry. them look at what you've got. The idea of sanding sealer is that it can be rubbed out with dry paper without clogging the pores too much.

The grey is probably the abrasive disintegrating through too much rubbing.

if you have shiny and dull patches then you have gone trough the sealer and back into the timber.

Allow the whole thing a good 24 hrs to dry off. You will probably need to give it another couple of coats of the sealer then sand again with 600 or even 800 grit. This way you won't cut straight back through the surface into the timber.

I hope this is a solid body guitar as oil on an acoustic would deaden the sound quality's somewhat.

As for a brighter shining oil there isn't one most oils are satin to dull. Fine sanding with 1200 grit and above will make the timber shine and also give the appearance of the finish having a higher shine. Sanding the Danish oil in with 1200 grit should also help to fill the pores of the timber.

Hope this helps a bit.

Cheers - Neil :)

[conwood]

Hi Pauli,
Just confirming u beaut admin's comments and will add some of my recent knowledge.

To get an oil sheen, as best as oil can do, I've found many very light coats rubbed with fine cloth. I even buff between oil coats. I am now experimenting with feast and watson fine finishing oil using the finest scourer I can get and then going to progressively finer cloth rubs.

I did read in an old woodworking book about oil sheens in the good old days when people had time. The author stated that 20 -30 or more coats of linseed oil over 12 months or so brought a good sheen.

If you want real shiny shellac is the go. Recently I did a project where I applied over 20 real thin coats coats just with a fine cloth, not a rubber and got excellent results. These were achieved over long periods of time, so the last coat is allowed to really harden then rubbed with 1200 grit. I then used rotten stone and parrafin oil for the final polish and am not sure if this step made a difference.

The process of polishing is reducing scratches to reflect more light.

I'm about to experiment with shellac as a sealer.

Keep learning.

Cheers,
conwood

[durwood]

You havn't said how many coats of sanding sealer you put on and whether it lacquer sanding sealer or another type.

Lacquer would dry real fast (a few minutes) If its lacquer you need about 3 -4 coats and start about 800 not 400 paper. As U beaut suggested let it dry out and see what you have. You have rubbed through no doubt.

Sanding sealer is a paint so it coats a surface with a plastic coating putting oil on top of it is just like putting oil on your car paint.

If you need to get a better gloss then you will have to go to a wax as you have said you don't have the equipment to further coat the surface with a clear.

[pauli]

Cheers for the responses guys.. I don't think it's a lacquer sealer, I only know the brand - feast and watson. I've only applied one coat, and that was with a brush, which seemed to me to be too thick.

Thanks for the info Neil, it is actually an acoustic, not a solid body (it's all solid woods though), and I did think that it would dampen the sound. I suspected the oil would really soak into the woods, unlike a french polish or lacquer which I'm under the impression would sit on the surface. In the course, all are finished with oil usually, and they actually sound fantastic, but I did want to go my own way and go with my instinct on the finish for look and sound, and had wanted to do an aerosol nitrocellouse lacquer. I have this stuff, VHT SP610 clear cost (an aerosol lacquer), but some test sprays on off cuts didn't turn out so well, so I gave up on it. The latest plan/solution was that if I used the sanding sealer, unlike the standard oil finishes these guys have, I would have created a bit of a barrier to the oil penetrating the wood - hopefully just leaving a protective oil finish on top of the sealer. But then again, like i said this was my first real attempt at wood working, let alone finishing!

New plan is, its now dry, so i'm going to try and cleanup whats left of the messy sealer with dry 400 then bring it back to 1200 as it was before I applied the sealer. The sealer that I haven't touched yet, I'll lightly dry sand with 800, and then i'm going to do another sealer coat, much lighter this time wiping on with a cloth, lightly dry sand at 800 again once it's dried, (and another one if it seems like it), then start in the with the oil and soft cloths (bit of everyones advice!).. I'm also going to investigate this fine finishing oil on some scrap if I can get some. Thanks very much for the advice - I'll check back in later to see if anyone thinks this is a ridiculous idea (im going very very slowly!) and also to update you and post some pics if it comes up ok.

cheers again, paul.

[shanelm]

Cheers for the responses guys.. I don't think it's a lacquer sealer, I only know the brand - feast and watson. I've only applied one coat, and that was with a brush, which seemed to me to be too thick.

Thanks for the info Neil, it is actually an acoustic, not a solid body (it's all solid woods though), and I did think that it would dampen the sound. I suspected the oil would really soak into the woods, unlike a french polish or lacquer which I'm under the impression would sit on the surface. In the course, all are finished with oil usually, and they actually sound fantastic, but I did want to go my own way and go with my instinct on the finish for look and sound, and had wanted to do an aerosol nitrocellouse lacquer. I have this stuff, VHT SP610 clear cost (an aerosol lacquer), but some test sprays on off cuts didn't turn out so well, so I gave up on it. The latest plan/solution was that if I used the sanding sealer, unlike the standard oil finishes these guys have, I would have created a bit of a barrier to the oil penetrating the wood - hopefully just leaving a protective oil finish on top of the sealer. But then again, like i said this was my first real attempt at wood working, let alone finishing!

New plan is, its now dry, so i'm going to try and cleanup whats left of the messy sealer with dry 400 then bring it back to 1200 as it was before I applied the sealer. The sealer that I haven't touched yet, I'll lightly dry sand with 800, and then i'm going to do another sealer coat, much lighter this time wiping on with a cloth, lightly dry sand at 800 again once it's dried, (and another one if it seems like it), then start in the with the oil and soft cloths (bit of everyones advice!).. I'm also going to investigate this fine finishing oil on some scrap if I can get some. Thanks very much for the advice - I'll check back in later to see if anyone thinks this is a ridiculous idea (im going very very slowly!) and also to update you and post some pics if it comes up ok.

cheers again, paul.
Hi Pauli,
I have just joined the forum this morning, and have had a similar experience with sanding sealer, and grain filler. I to, am new to fine finishing, and also looking for just the right finish for my projects.
I applied the same F&W sanding sealer to one of my recent projects, with equally disasterous results. I had left mine dry for a whole week before I attempted any sanding. I started with a suface (KWILA) sanded progressively down to 1200 grit, looked great, but wanted to fill the open grain, so on advice from a local supplier, applied a grain filler, which worked reasonably well, followed by the sanding sealer.
From the get go, the sanding didn't feel right. The sealer still had a very slight tackiness to it, giving the impression that it hadn't completely dried.
Hence, leaving it for a week. Well, every piece of sandpaper clogged, one after the other, and nothing convinced me I could save this finish.
If I went through to the bare timber, I couldn't get it to feather out at all.
In the end I had to hit it with a belt sander and 80grit, and went back to scratch. I was later told by someone else, that sanding sealer should be applied by brush, then the excess removed by scraping it with glass.
Anyone else heard of this technique? Anyway, thought I'd share my plight.

[pauli]

Gday again.. Just an update for you, particularly Shane -

On advice from my girlfriends father, I got stuck into the messed up areas with 0000 grade steel wool .. it took half a day of hard work, a whole pack of steelwool and a bl**dy sore arm, but it;s come up beautifully.. natural glow and reflection to it, before any oil has even gone on... i'm sure some skin oils from my hand have gone in, but its fantastic.. its' level, smooth as, and has a nice natural reflection of light, not shiny exactly but good..

I've even managed in one area where I feel i over sanded, to recoat with the sealer (this time using a soft cotton cloth), let it dry for 2 hours, dry sand a litte with 400 just to get level, then get into it with the steel wool again.. the bit that i've oiled for testing has come up promisingly, so i'm going to polish in the oil with the steel wool for the rest of it now. I'll post some before and after pics soon.

cheers,
Paul.

[durwood]

The Feast Watson sanding sealer is a turps based product. This should be noted on the tin for thinning or clean up.

Any turps based paint is going to be a slow drying material. Most turps based paints are based on synthetic resins which cure by joining with oxygen in the air. Thats why they get a skin on the top of the paint once the tin is opened.


They can take months to dry hard, if you put on too thick a coat it will get a skin on it and the underlying material will be slowed down considerably.

These types of paint are not the ones to use if you intend rubbing back and trying to produce a top finish you will have an up hill battle getting a good result.

Pick a paint with a fast drying time, one which has in it a fast drying solvent. Such as shellac (metho) or lacquer (lacquer thinner) or a polyurethane with a hardener which will dry rock hard in hours not months.

You can then apply and rub them as much as you want as they dry in a short time keep away from water or turps materials if you want to work the paint by rubbing, buffing or polishing.

If you are not sure of the type of material and its not obvious on the tin look up the paint on the net, details of the ingredients are in the technical data sheets.
eg; if you look up Feast Watson on google the top hit is the data sheets for all their products.

[silentC]

I've used that Feast and Watson product a lot. When you sand it, the dust clogs together and resembles resin. It forms lumps on the paper very quickly, and you need to clean the paper often. I've tried leaving it for a few days but it doesn't seem to make any difference.

Once you rub it back, it's fine. I've used it under various oils and it comes up nice.