Pore-filling - How Do You Know When You're Done?

[Johnny Foreigner]

I've now had 3 stabs at mahogany pore-filling - once on the Six and twice now on the Wol.

Each time, I've followed the instructions. I'm using Stewmac waterbase grain-filler. The Six was mahogany of unspecified origin and the Wol was African mahogany.

And each time, I've found it impossible to tell if the pores are filled - until putting the finish on and getting to the point where it's shiny. then i can hold up to a light source and still see the pores while the rest of the wood reflects the light.

So my question is two-fold:

1) how many rounds of pore-filling should I be expecting to do on mahongany? I was figuring on one, but clearly I was wrong. What about black limba (my next build)?

2) how do I tell when I'm done? Looking reeeeeaaaallllly hard hasn't worked so far!

[RestorationAD]

I've now had 3 stabs at mahogany pore-filling - once on the Six and twice now on the Wol.

Each time, I've followed the instructions. I'm using Stewmac waterbase grain-filler. The Six was mahogany of unspecified origin and the Wol was African mahogany.

And each time, I've found it impossible to tell if the pores are filled - until putting the finish on and getting to the point where it's shiny. then i can hold up to a light source and still see the pores while the rest of the wood reflects the light.

So my question is two-fold:

1) how many rounds of pore-filling should I be expecting to do on mahongany? I was figuring on one, but clearly I was wrong. What about black limba (my next build)?

2) how do I tell when I'm done? Looking reeeeeaaaallllly hard hasn't worked so far!

You tell me and we will both know.

I have had similar experiences with the waterbased fillers. I think the instructions are wak... they say let stand for 5 minutes then wipe away, well it doesn't harden enough in 5 minutes so the rag dips some out of the pores partially filling. So I ended up coating the guitar and then waiting until I could barely get it off and squeegeed most of it off. Then went back after it was dry with a block and 400 grit and leveled it. That kinda worked... still not perfect though. I then said a few choice explicative, closed the can and put it on the shelf. I then used the top of the can to mix epoxy on for the next guitar. That worked better but involved more sanding.

Move to the microbead filler from LMII.

Problem should be solved by that.

[DC Ross]

The Colortone / Target waterbased grain filler is, to put it mildly, crap.

http://projectguitar.ibforums.com/index.ph...c=43029&hl=

RAD is right, their instructions were written by someone who had never used the stuff. I tried every possible application technique that I could think of, and finally was able to fill the pores by sheer will and brute force

[ScottR]

Move to the microbead filler from LMII.

Problem should be solved by that.

I must admit I'm looking forward to responses on this as well. Your last comment implies that the jury is still out on the microbead filler....?

SR

[Johnny Foreigner]

You know, I remember reading that thread at the time and making a mental note to refer back to it.... my memory is going.

So I may not have stirred as thoroughly as I should, and maybe that's part of the problem.

But if the consensus is that the stuff is crap then I'll happily give up and move over to the LMII stuff.

[RestorationAD]

Move to the microbead filler from LMII.

Problem should be solved by that.

I must admit I'm looking forward to responses on this as well. Your last comment implies that the jury is still out on the microbead filler....?

SR

Mine is still in route. I will let you know.

I think Huf uses it and likes it. He should chime in and say....

[Woodenspoke]

Anything finishing is a pain. I always thought the WB stuff had too low a solids content and just sunk. It was constant refilling with marginal results. The alternative is almost as bad as its hard messy and just as much trouble to keep it clean (oil based filler). makes you want to figure out how to dip a guitar in epoxy..

I always felt finishing is learning to suffer...

I have tried using a shellac with microbeads to fill pores, this also has its draw backs but dries fast enough to repeat. Almost like adding a French polish only thicker.. I have even used a cooking powder (baking soda) to increase bulk in shellac.. It works as the Baking soda turns clear.

Just my thoughts on suffering

[westhemann]

I filled my mahogany beast with two heavy applications of medium CA and years later it was still flat...I mean,now it is dead,but the finish was still fine.

I did not sand back down to the wood...I left a thin,uniform base of CA over the entire guitar,then cleared over that.

[RestorationAD]

Anything finishing is a pain. I always thought the WB stuff had too low a solids content and just sunk. It was constant refilling with marginal results. The alternative is almost as bad as its hard messy and just as much trouble to keep it clean (oil based filler). makes you want to figure out how to dip a guitar in epoxy..

I always felt finishing is learning to suffer...

I have tried using a shellac with microbeads to fill pores, this also has its draw backs but dries fast enough to repeat. Almost like adding a French polish only thicker.. I have even used a cooking powder (baking soda) to increase bulk in shellac.. It works as the Baking soda turns clear.

Just my thoughts on suffering

+1 everything spoke said

I hate finishing.

I filled my mahogany beast with two heavy applications of medium CA and years later it was still flat...I mean,now it is dead,but the finish was still fine.

I did not sand back down to the wood...I left a thin,uniform base of CA over the entire guitar,then cleared over that.

Isn't it in the firewood pile now?

That is not a bad idea.... but CA done wrong can be blotchy. And if you sand through you have to fix it or the color will be uneven.

I have used the thick CA and sanded all the way back to the wood... it is just a bit of hard work.

I hate finishing.

[Drak]

Use 2-part epoxy or CA glue.

Next question?

[Workingman]

Can't help with the finishing but don't burn anything that was grain filled with CA indoors. The fumes are very bad.

[low end fuzz]

hmmm;

on the few projects ive wanted a very level finish and had to pore fill, ive only needed one coat of WB filler (stew mac) and some touch ups;

i sand to 180; fill the pores; i use my hands, i never remeber to but a brush; rub it on, and i dont even sqeegee it off; resand 180, look for dips in the light, slop on more in spots i need it (i just use a popsicle stick) resand spots and finish; i always level my finish at least twicw during the process, which could be the secret; but i find the filling the part that gives me the least greif; thats on ash and walnut mostly

[DC Ross]

hmmm;

on the few projects ive wanted a very level finish and had to pore fill, ive only needed one coat of WB filler (stew mac) and some touch ups;

i sand to 180; fill the pores; i use my hands, i never remeber to but a brush; rub it on, and i dont even sqeegee it off; resand 180, look for dips in the light, slop on more in spots i need it (i just use a popsicle stick) resand spots and finish; i always level my finish at least twicw during the process, which could be the secret; but i find the filling the part that gives me the least greif; thats on ash and walnut mostly

Are you using the ColorTone or TimberMate?

The ColorTone stuff has a very low viscosity (i.e. watery), and sinks into the pores so much that it takes way more than a couple applications, especially on woods like Mahogany.

[low end fuzz]

colourtone;

like i said; never needed more than one complete coating; but to be fair, these are not mirror gloss finishes, the most is high gloss, but still no noticable pittings in either of the ones im looking at now; theyre about 2 yeas old

[westhemann]

Isn't it in the firewood pile now?

Yeah,but not because of pore filling.My exploder is also sealed with CA,and that is bubinga...even bigger pores than mahogany...again,two applications of CA,then Finish,and it looks the same today as then

I still have the neck,also mahogany,and sanded back to bare wood for this project.

The best thing I ever did was listen to Drak suggest medium CA applied with a business card.It only looks splotchy if you sand through,but anything is that way....so don't sand through.It is ridiculously easy if your surfaces are properly prepared(no high spots)

[westhemann]

Taken today..right now...did not even bother to polish it,as you can see.....this is what?Two years?Three?

[Southpa]

I also tried Stewmac's clear, waterbased filler and had no success. Sand back and then the fingernail still digs into some pores. I usually have a knack for making things work. I was talking to a painter at work and suggested maybe he would have some results as he is interested in using environmentally friendly materials as per specs issued by our respective government regulations. He knows that epoxy and CA works fine but simply doesn't have the time. So he ordered a couple cans of the waterbased filler and later told me it sucks. The guy is a pro and works with an assortment of mahogany type woods every day but cannot use kid gloves while sanding, for example, everything has to be done with palm sanders etc, no hand sanding. Otherwise he would be backed up for weeks and nothing would get done! So maybe Stewmac will clue in and take the crap off the market. The first time I open a can I remarked, "Huh, looks like a can of sperm!"....maybe IT IS!

[Drak]

He knows that epoxy and CA works fine but simply doesn't have the time

So let me get this straight, he knows what works,

but would rather spend the time and money experimenting on things that he's not sure of or that don't work?

...But he does have the time for that...

Seriously, I must be missing something really obvious here...

[twangmeister]

Hi Guys,

I'm a new poster here but I have been lurking for a while. I wanted to jump in on this pore filling thread as I have a bit of experience over th elast 3 or 4 builds and I think I have it down pretty good.

Firstly, poor filling isnt rocket science. Its just a metter of a couple of techniques which will produce glass like finishes everytime.

The stuff you want to use is called Timbermate - Its an australian product that Stewmac now sell.

Prep and sand your body and spray a sealer coat of nitro ( about 80% thinners ) -

Scoop some into a bowl and add enough water to make a slurry like consistency that you can roll or brush onto your guitar.

You can add a tint at this point if you wish to make the grain fill a feature on your guitar and use transparent color-tinted coats.

I use a small foam roller to roll the filler onto the guitar , you can also brush it on if youi prefer. It dries quickly as the coats are thin.

[twangmeister]

When its completey dry, sand the filler back with about 600 grit sandpaper. Keep a vacuum and dust mask handy, its messy work.

Its pretty easy to gauge how much sanding to do. This stuff is a pleaure to sand, it comes over very easily !

This is the back complete

Sand the entire body smooth and then hit it with another sealer coat of nitro.

I'll then repeat the above process AGAIN. So thats 2 lots of grainfilling and sanding back.

Edited November 22, 2010 by twangmeister

[twangmeister]

Now I spray a base coat of white nitro over the sanded body until its completey covered.

Mix my colours up for Seafoam green

And spray

[twangmeister]

At this point, I can still faintly see a ripple efect of the grain telepgraphing thru the finish - DON'T PANIC !

Start your clearcoat schedule now and build up a decent amount of clearcoats on the guitar ( approx 5-6 coats ) as we are going to level the finish and see gauge where we are up to.

You need to wetsand the finish now but we are not going for an aggressive sand, we just want to level the finish out and see any dips or low points that need attention. Keep water away from any holes. If you see anything that is going to be a troublesome to fill with the next 3-4 coats of clear, you can drop fill them now. You will also eliminate any signs of grain with this sand. All you will see after this is completed are random shiny spots that indicate we still need to build the clear coats up some more.

At this point, I can see that its nearly there, I just have a few shiny spots that are still visible. I now spray another 3-4 coats and let it sit.

Repeat the wetsanding process this time eliminating all of the shiny spots and buff thru your compounds.

[twangmeister]

As mentioned earlier, a variation is to add a tint to the Timbermate before you fill the guitar - I do this when I am going for a tinted finish. In this case, I've added some black tint ( it looks gray until its sanded back and hit with some lacquer).

Build thread referenced in these posts can be found here -

Seafoam Strat - http://s637.photobucket.com/albums/uu98/da...itar/?start=all

Cherry Red Tele - http://s637.photobucket.com/albums/uu98/da...itar/?start=all

Edited November 22, 2010 by twangmeister

[verhoevenc]

For z-poxy pore fill there's a great video on youtbue by MDLuthier. Yes, I read, you don't want epoxy fill... but for if you change your mind... it's there and leaves out no detail.

Chris

[Johnny Foreigner]

wow, interesting discussion.

the Justin Timberlake looks more appealing than the Zed-Poxy at this stage....

At least I can throw out the colortone crap with a clear conscience.