Pore and grain filling on Mahogany

[Steve_Karl]

I'm trying to get a handle on the general process of finishing a mahogany body.
I'm about to do my first one soon, ( a new, raw one ... not the one in the pics )
...and I'm hoping someone will have a look at the pics and either confirm my observations or correct me?

I had a real good look at my current mahogany strat body and wanted to confirm with you ( see the pics ) that the dark dots and sometimes longer lines are the pores that we're sometimes talking about. It looks like these were filled with something darker than the natural wood color? Would that be your evaluation also? And the idea of "grain filling" ... see the 3rd pic.

http://sightsea.com/renders/finish/pores_2.jpg - - - smallest pores?

http://sightsea.com/renders/finish/pores_1.jpg - - - small grain or elongated or grouped pores?

http://sightsea.com/renders/finish/grain_1.jpg - The dark strip going through the low A's ferrule . . . that darkness is accomplished by grain filling?

Thank you,


Steve

 

[Tonar8352]

Steve,
You are correct; that is darker pour filler that has been applied after several wash coats of clear.  The maker wanted to maintain the original color of the wood but chose to enhance the grain lines with dark mahogany grain filler.  In order to accomplish this look follow this finishing schedule.

1. Prep and sand wood with 280 or 320 abrasive.
2. Blow the surface clean with high-pressure air.  Make sure to get the entire sanding residue out of the deep gain pours.
3. Shoot 2 wash coats of finish on the body.  A wash coat would be 2/parts of thinner to 1/part of finish.  Let that dry over night.
4. I would use McFadden’s Mahogany grain filler from Lutherie Mercantile.  Fill the grain according to the direction on the can.  
5. Let it hang a couple of days and then start your clear coats.  You may want to do a second filler coat if the pour filler is really shrinking into the grain and you see dimples.

Good luck

 

[Steve_Karl]

The wash coats ... can they be tru-oil?
I was hoping to use tru-oil as a finish.

Thank you!

Steve

 

[Tonar8352]

Steve,
I do not think that will work.  I believe you will have to hard finish the guitar to get the same effect but you can always try it on a sample board and see what you get.

 

[Steve_Karl]

It's not critical that I get the same exact effect.
I was planning on following this tutorial: http://www.lmii.com/CartTwo/TruOil.htm

My initial post with the pics was mainly to discover if I was actually seeing the pores and seeing that they were filled with a darker material,
...connecting the visual of my current guitar, which I had never really examined closely before, with the verbal input and terms that I've been getting here at the forum.

I did get some scraps from a friend and will be doing some testing first.

Thank you!

 

[Keyser Soze]

You can use Tru-oil as a sealer, but I'd suggest thinning it 3 to 1 with mineral spirits.  As Tonar mentioned the purpose of sealing prior to filling is to prevent to dark filler from also acting as a stain to the rest of the wood.  You don't need a really thick layer to accomplish this.  Actually really thick layers often make it difficult to get the filler into the pores - thinner is often better

You would then need to use an oil compatible grain filler.  If the filler is not compatible with oil based products that would also interfere with getting it to stay in the pores.

 

[Steve_Karl]

Thank you!

 

[-CB-]

Instead of tru-oil, good old shellac, like Bullseye... thinned half again with denatured alcohol.  Makes a wonderful seal coat.

 

[Steve_Karl]

Thanks CB!

It's in my notes now.