Walk me through sanding and finishing with Tru Oil

[jeeeemes]

So I recently ordered a black korina jazz master body from Warmoth and should be receiving it early next week. After some research, I've decided to do a Tru Oil finish since it seems to look beautiful on black korina and seems much less meticulous and time consuming than a nitro finish. I was wondering if anyone that has successfully done a Tru Oil finish on black korina could walk me through the process from beginning to end?

So far, this is what I figured I'd do after my research:

-- sand body to 400
-- sand body to 600
-- wet sand (400 or 600 grit?) to fill in the grain a bit
-- first coat
-- wait 2-4 hours, second coat
-- wait 2-4 hours, third coat
-- dry overnight, sand to 600 again
-- fourth coat
-- wait 2-4 hours, fifth coat
-- wait 2-4 hours, sixth coat
-- dry overnight, scratch in circles with synthetic steel wool (fine? 0000?)

For each coat, I've read that it can be better to use a small amazing of Tru Oil on a square of lint free cotton shirt that's been balled up and use a French polish technique as opposed to flooding the body with oil and wiping down. Any suggestions or corrections to my method would be appreciated. Thanks!

 

[vikingred]

This sounds really cool, I've been looking into Tru-Oil as well, and I just grabbed an Extra Light Swamp Ash body, and I'm wondering if this same method would work with Swamp Ash?

 

[amigarobbo]

You might need to put grain filler on to fill the open pores of swamp ash, if you want a perfectly flat coverage.

 

[stratamania]

I'd suggest using Birchwood Casey Gun Stock Sealer & Filler, to seal and fill pores prior to using their tru oil product.

Also use thin layers of tru oil and don't scrimp on drying time as it will gas off for some time.

 

[jeeeemes]

I'd suggest using Birchwood Casey Gun Stock Sealer & Filler, to seal and fill pores prior to using their tru oil product.

Also use thin layers of tru oil and don't scrimp on drying time as it will gas off for some time.

Thanks for the suggestion stratamania. Follow up question: assuming I should substitute the Birchwood Casey grain filler for my Tru Oil wet sanding step, should I sand again to 600 after letting the grain filler dry?

 

[Fat Pete]

What were you planning to use for the wet in your wet sanding step?

 

[jeeeemes]

What were you planning to use for the wet in your wet sanding step?

I was going to wet sand with Tru Oil to fill with the slurry mixture of Tru Oil and sawdust from previous sanding.

 

[Fat Pete]

What were you planning to use for the wet in your wet sanding step?

I was going to wet sand with Tru Oil to fill with the slurry mixture of Tru Oil and sawdust from previous sanding.

I think that would work fine, but using a clear grain filler might help retain more of grain's detail.

 

[jeeeemes]

What were you planning to use for the wet in your wet sanding step?

I was going to wet sand with Tru Oil to fill with the slurry mixture of Tru Oil and sawdust from previous sanding.

I think that would work fine, but using a clear grain filler might help retain more of grain's detail.

That sounds like a plan, I'm assuming I should sand to 600 again after the grain filler dries before starting my Tru oil applications?

 

[bagman67]

You actually don't want to go that fine.  Stick with 320.  Leave yourself a little "tooth" for the Tru-oil to build up.  If you apply to a perfectly slick surface, you actually increase the likelihood of finish failure.

 

[vikingred]

You actually don't want to go that fine.  Stick with 320.  Leave yourself a little "tooth" for the Tru-oil to build up.  If you apply to a perfectly slick surface, you actually increase the likelihood of finish failure.

Ok Bagman, if you don't mind, can you please take the OP's sequence and show where the 320 goes, and what's ok as is:

-- sand body to 400
-- sand body to 600
-- wet sand (400 or 600 grit?) to fill in the grain a bit
-- first coat
-- wait 2-4 hours, second coat
-- wait 2-4 hours, third coat
-- dry overnight, sand to 600 again
-- fourth coat
-- wait 2-4 hours, fifth coat
-- wait 2-4 hours, sixth coat
-- dry overnight, scratch in circles with synthetic steel wool (fine? 0000?)

 

[bagman67]

-- sand body to 400-- sand body to 600 -- OMIT-- wet sand (400 or 600 grit?) to fill in the grain a bit  [possibly repeat this step-- first coat-- wait 2-4 hours, second coat-- wait OVERNIGHT 2-4 hours, third coat-- dry overnight, sand to 400 600 again-- fourth coat-- wait OVERNIGHT 2-4 hours, fifth coat-- wait OVERNIGHT 2-4 hours, sixth coat-- dry overnight, scratch in circles with synthetic steel wool (fine? 0000?)

If  you're after a semi-matte finish, yes, use the steel wool.  If you want a gloss finish, you can wetsend on a schedule similar to lacquer, with a similar cure time before you get started as well.

Also, I'm not convinced you'll have enough tru-oil on that body after only 6 coats, but that will really depend on your desired effect. 

I substituted an overnight wait time because if you build this stuff up and it doesn't cure adequately before the next layer goes on, you could wind up in a gummy hell from which the only respite is a strip job.

The short form of the answer to the question "How do I make sure I get a good finish?" is "Take your goddamn time; there is no such thing as a shortcut; and always practice on scrap of the same species before you apply anything to your actual body."

 

[vikingred]

-- sand body to 400-- sand body to 600 -- OMIT-- wet sand (400 or 600 grit?) to fill in the grain a bit  [possibly repeat this step-- first coat-- wait 2-4 hours, second coat-- wait OVERNIGHT 2-4 hours, third coat-- dry overnight, sand to 400 600 again-- fourth coat-- wait OVERNIGHT 2-4 hours, fifth coat-- wait OVERNIGHT 2-4 hours, sixth coat-- dry overnight, scratch in circles with synthetic steel wool (fine? 0000?)

If  you're after a semi-matte finish, yes, use the steel wool.  If you want a gloss finish, you can wetsend on a schedule similar to lacquer, with a similar cure time before you get started as well.

Also, I'm not convinced you'll have enough tru-oil on that body after only 6 coats, but that will really depend on your desired effect. 

I substituted an overnight wait time because if you build this stuff up and it doesn't cure adequately before the next layer goes on, you could wind up in a gummy hell from which the only respite is a strip job.

The short form of the answer to the question "How do I make sure I get a good finish?" is "Take your goddamn time; there is no such thing as a shortcut; and always practice on scrap of the same species before you apply anything to your actual body."

So.........you posted earlier about 320.  Where are you saying to use the 320?  Sorry but I'm trying to get some precision on this.  320 is better than the 400 you mean?

 

[bagman67]

If 320 is what you have, that's fine; if 400 is what you have, that's fine, too.  400 is not necessary but won't hurt anything, but 600 and up is probably counterproductive unless you are final-wetsanding a finish.  IF you have 320 on hand, don't bother using (and certainly don't bother buying) 400 for a pre-finish or between-coats scuff; but if you don't have 320 and have 400, use the 400 if it will save you a trip to the hardware store.  I use 320 on my axes and have never had any problem.

 

[stratamania]

Assuming you use the sealer and pore filler I mentioned you don't wet sand it. You use a couple of coats of it and let it do its job.

The method of putting on a fair bit of tru oil and sanding while wet is to get the wood dust to mix with the tru oil to fill the pores.

If you have already sealed it with a sealer and pore filler there is no point wet sanding.

And yes for a body I would build up probably a lot more than 6 thin coats.

In the case of Vikingreds very light ash body that will have open pores for sure. So you might need to build up with the sealer and pore filler a few times.

Also pay particular attention to the end grain and sides.

Whilst building up thin layers, every two or three an extremely light touch done dry with some 400 to knock down any blemishes may be needed. But if you've done it thin enough this should not happen too much so a light once over now and again is all that should be needed.

Now when you've built up several to many thin layers and lovingly let it dried for a good amount of time you are now at the final finish point.

Remember you aren't burnishing you are finishing so the most you need is 400 and 600, possibly some 800. It's not lacquer otherwise I may have suggested finer grits.

If the layers have been built up thinly and dried, there should be no bumps, orange peel or other warts to get rid of. So a light touch with some 600 and 800 is all you need. Dry not wet.

Finally get some Birchwood Casey Gun stock wax and rub it on with a lint free cloth and give it a good buffing with another lint free cloth and it should look very good indeed.

Now you might say I've seen a guitar maker on YouTube pouring tru oil on and sanding in the slurry, and I've seen another guy who had to do final wet sanding of it and get a buffing wheel to end up with a decent finish after building up thick layers. I say if you aren't in a rush and trying to take shortcuts that approach isn't the way to go.

Remember this isn't a lacquer that when sprayed will orange peel.

And for anyone who is aghast at the idea of Gun stock Wax, it's going to do a fine job and improve the durability of the finish. Not to mention it isn't lacquer or poly

Finally practice on scrap if you aren't certain.
Take your time.
It's an art as well as a craft.

 

[jeeeemes]

Thanks for all of the responses everybody, it's been a big help!

I think what I'm planning on doing now is, prior to starting Tru Oil coats, using the Birchwood Casey grain filler and sealer. Does anyone have any recommendations on how many coats of this I should use before Tru Oil application, whether I should sand between grain filler / sealer coats, and what grit to use in this stage of the process?

Also to answer and previous questions, I was planning on using 0000 synthetic steel wool after the final coat to get to a matte looking finish.

I finally feel like I'm just about ready to get started! Should begin sometime this week once the stuff arrives.

 

[stratamania]

For the sealer on the Korina try two coats. Some of this is a feel thing and that's where the art comes in. If it looks sealed you'll probably tell. The sealer tends to dry and have less working time than the tru oil itself.

When you get to the final coat depending on how they have built up it may be matte enough if you don't buff it. But if you need to take a little shine off something like 1500 grit ought to do it.  I tend not to use steel wool as I find it messy.

If you get a scrap bit of wood you can test out methods as you are going along.