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I think I found a pore fill procedure that works pretty good (for me)
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enalnitram (Martin Lane)

Total Topics: 47
Total Posts: 338
So I'm knee deep in pore fill. I've found out the hard way, that there is no "well I'll just get that done in the next few days" with this stuff. I'm in it for the long haul, and it will be done when it is done, not necessarily when I hope it will be.

So I stained my guitar using dyes. Then I sealed with a few coats of 1 lb cut shellac. my dyes are transtint diluted with distilled water. and my shellac is dewaxed blonde flakes dissolved in 190 proof everclear.

next I used pore o pac filler, the mahogany colored stuff. i added a little naptha to the mix as john hall recommends. i tried an old credit card at first, which sucks. I quickly ditched it, and just started using my fingers. works great. I am wearing nitrile gloves, of course. I worked the pore o pac in, rubbing it in a circular motion, in a little 2-or-3 inch area. just before it dries, I wipe it off with a rag (a new white tshirt, actually). it took me about (who's counting) maybe 2 hours to go over the whole body. doing it this way took care of most of the pores.

Ideally, I'd do the pore o pac again, but doing it darkened my finish so much, that I decided to continue next with pumice pore fill, ala french polish.

I followed the milburn method, without shellac, only a preloaded pad, alcohol, and pumice. working on a little 3-inch area on the back, after about 10 mins, the pumice filled the pores completely and left me with a very nice smooth area.

HOWEVER, the pad also wiped away my dyed wood color, which is kind of a drag.

so I'm at a crossroads now. I'm happy that I got a smooth surface. I could do the whole guitar this way, and then re-stain, and hope for an even color appearance. Or, I could fix the area, re-seal, and then pumice the guitar with shellac (rather than alcohol) and hope for a good result, which preserves my stain/dye color.

If it weren't for my dyed wood I'd be home free. should I have dyed the wood after pore filling?










May 18, 10 | 6:10 am
Ken Hundley

Total Topics: 40
Total Posts: 2169
I can't see the issue on the back, it looks good! When to stain is a tough call....are you looking to stain the wood, or tint the finish? Staining the wood will leave stain in the pores, and to my opinion, generally give you more contrast betweent he light and dark areas. Tinting the finish will give a much more uniform color to everything, though may not be as clear or deep.

May 18, 10 | 9:28 am
Adaboy

Total Topics: 64
Total Posts: 509
I wish I could answer your questions Martin. It won't be long till I'll be trying pore filing for the first time. Right now I'm leaning toward using CA.

Look forward to hearing someone answer your questions.

May 18, 10 | 9:29 am
enalnitram (Martin Lane)

Total Topics: 47
Total Posts: 332
thanks Ken, over the last few weeks I've gotten lots of practice covering my finish flubs!

After spending lunch hour at woodcraft, I have a new plan. I plan to "cheat" a little with my french polish technique, and wipe on coats of shellac and then cut each back with 600 grit paper. this will fill the pores the rest of the way. then i'll apply bodying sessions after that.

i know part of the whole idea with the french polish technique is amalgamating the layers so that you have a cured finish where the coats blend into one another...I'll [maybe] try that next time!

May 18, 10 | 9:58 am
enalnitram (Martin Lane)

Total Topics: 47
Total Posts: 332
Ken, I didn't answer your question. I like stained wood over tinted finish. I guess that's why I wanted to do it the way I did. I'd like to preserve it. We'll see what happens.

I did test on scrap, and got none of these issues. like I've said before, it seemed easy to get a good looking dinky test piece. the guitar turned out to be a different creature. I didn't have a scrap guitar to test on. when I was FP'ing my test pieces, my wiping coats were probably going on much thicker and building much easier, cuz I was just working over a little area, over and over. the pore filling was done, just like *that*.

May 18, 10 | 10:03 am
enalnitram (Martin Lane)

Total Topics: 47
Total Posts: 332
Looks like it's working.

Before.


After.


I have a hook on my workbench pegboard that fits thru the soundhole.




May 18, 10 | 2:52 pm
Kevin Sjostrand

Total Topics: 84
Total Posts: 981
Martin,
I think you will make it turn out just fine. Is your guitar secure hanging there......what if a little shaker happens???? Just worrying a little for you.

Kevin

May 18, 10 | 4:18 pm
enalnitram (Martin Lane)

Total Topics: 47
Total Posts: 332
Thanks. Yeah, it's on a hook. Then there's a little bar that touches the bridge mask that keeps it stable.

We don't get no shakers here in Mishy gun. You must be from Californy.

May 18, 10 | 4:49 pm
Ken C

Total Topics: 30
Total Posts: 554
Love to contribute here, but in all my years of woodworking, I have never french polished. I'm liking the look though!

Ken

May 18, 10 | 6:10 pm
Kevin Sjostrand

Total Topics: 84
Total Posts: 981
Californy is the place you awt to be.......so load up your truck and move to
Beverly! Plenty of shakers here.

May 19, 10 | 6:07 am
DaveH

Total Topics: 5
Total Posts: 20
Martin,

We can all agree that Pore Filling is a complete PITA. It's not so difficult to do, but it's difficult to get the results we all want (100% filled and level pores). Balancing that with the optimum acoustic top-coat thickness...... well you get the idea! I'm rather traditional, in that I use paste-type fillers, usually oil based (i.e. Behlen's Pore-O-Pak). When using this type of filler, whether on a Guitar or End Table, you have two distinct approaches. They are:

1. Fill first: Here you apply the paste fille to the raw wood. You have to realize that paste fillers are made up of mostly filler and pigment (typically lots of pigment - but that's OK). Whether you apply one or three coats is irrelevant. After the filler has sufficiently dried (shrunk, hardened, call it what you want), you will need to do a thorough sanding of the wood. 220 grit is probably a good balance. In essence you want to remove the pigments (color) from the flat/non-porous area of the wood, exposing raw wood. You have to realize that oil based fillers (with lots of pigment) do not soak into the wood, but rather sit up on top. You'll go through a bunch of sand paper, but you can easily open up and expose the bulk of the wood for either top coating or an application of dye. Because dye's don't rely upon pigment for color, they will readily aborb into the wood and give you the color you desire. ABSORBTION WITH DYE'S IS NOT A PROBLEM. Once you have applied the dye you will want to apply a couple coats of sealer to lock in the color. Don't skip at this point, especially if you are using Shellac or Nitro. You want to provide a barrier between you and the dyed wood. Shellac and Nitro both chemically bond (etch) into the previous coat. So sanding between coats, especially at this point is not important. Once you've got the pores filled (relatively), color correct, and color locked in the world's you oyster!

2. Color First, Fill Second: This was your first approach, and actually a viable approach. In this case you finish-sand the work and then dye to attain the proper color (let's assume dye rather than stain, because they are not the same). After application of the dye, you again need to lock the color in. As above, don't skimp. You need to provide an adequate barrier for protection. You also want to apply enough sealer/finish to the surface so that you can lightly sand the surface to a relatively smooth finish and not break through to the color. While dye soaks deeply into the wood (assuming proper application), it still can be disturbed by sanding. Once the sealer/barrier coats are applied you will be able to apply pore filler, but still have enough protection to sand off the excess pigments and filler. The more dilligent you are with the removal of the excess pigments and filler, the better. After application of the pore filler coats you will again need to sand the surface to remove the excess residues (pigments). This will remove the extra color and "cloudiness". After sanding, you will again eed to apply some sealer coats. If possible, apply the sealer coats with some form of spray, whether "rattle cans" or with a spray gun. This will seal the pore filler and not soften or scrup the filler. Remember that "padding" or rubbing the sealer coat will disturbe the surface, and start to remove finish, especially if using Shellac over Shellac, or Nitro over Nitro. I believe that this was your original problem.

Step back and look at finishing from each layer. In the above you want to handle each layer in the optimum fashion. Trying to look at the situation as a whole is sometimes to overwhelming.

Sorry for the incredibly long response, but I've taught finishing classes in the past and this explanation/approach actually made sense to a few people!


May 25, 10 | 2:39 pm
enalnitram (Martin Lane)

Total Topics: 47
Total Posts: 332
Thanks Dave,
that helps a lot. It also actually verifies my current situation, and makes me feel better about what I decided to do. I was unhappy with how the finish was looking, so I started over, and sanded down to wood, leaving only the dark pore filler filling most of the pores. Then I stained again using transtint-dye-diluted-with-distilled-water. After I got a light reddish brown tint, I wiped on minwax dark walnut stain. the key here was to wipe the stain off the rag before applying it to the guitar, to get an even application that wasn't too too dark.

I'm gonna let the stain dry a few days and then apply shellac seal coats. The surface is good and smooth. It's looking good. The guitar is quite dark now, but the eventual owner likes it that way.

When doing finishes like this again in the future, I think I'm gonna pore fill first, from now on.

May 26, 10 | 4:32 am
blues creek guitars Authorized Martin Repair Ctr

Total Topics: 52
Total Posts: 1011
I guess you are learning that there is more than one way to do this part. Finishing is as much about technique as it is about what product you use. If there is one piece of advice I can hand out is this , when you think you are done , do it 2 more times.
While I do not FP I use nitro , it is not uncommon to still have to drop fill a spot or two. There are so many different fillers out there . I do avoid the water based and acetone based ones as they flash off to fast and you can't get them worked in well.
Finishing a guitar is about patience . You may spend more time on finishing a guitar than the building of it.

John Hall
Blues Creek Guitars Inc.
Authorized CF Martin Repair Center

Jun 01, 10 | 3:50 am
enalnitram (Martin Lane)

Total Topics: 47
Total Posts: 332
Thanks John. Having one application of pore-o-pac, and sanded down to wood, still left lots more pores to fill. but I'm in a good place now, doing the rest with pumice.

I cheated a little bit, though. I wiped on shellac, sanded the ridges off with sandpaper, rubbed, repeat. It worked very good. I'm almost ready to do bodying.

shellac/pumice really lightened things up, somehow. I just don't understand why things behave as they do, sometimes, but I still like it.




Jun 01, 10 | 8:43 am
enalnitram (Martin Lane)

Total Topics: 47
Total Posts: 332
Getting closer. Here's the top.





And another shot of the back where you can see the binding.




The neck looks much better now that I've re-done it.




Jun 02, 10 | 7:45 pm



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