Pore Fill Challenge: Extreme

sequoia

sequoia

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Picture below of a ziricote back that is going to be an extreme pore fill challenge. Sanded out to 320. These are not so much pores as crevasses. I've tried to fill these things in ziricote before and it took forever and was a lot of work using a clear filler and many, many subsequent coats of shellac. It worked. Sort of.

I came across a Robbie O'Brian video of pore filling using saw dust and shellac and thought this might be a good time to try it. Anyway, these sorts of "pores" are beyond my usual methods. Has anybody tried this method? Picture below of wood in question and link to O'Brian's Tips du Jour video.

DSCN7250.jpg

https://www.youtube.com/watch?v=EcRc1cJrgtU
 
Spray on a sealer. Mix some black water based dye into some sheetrock mud. Apply with a credit card.... sand back... another coat of sealer reapply until filled. Don't sand back through the sealer or the black dye will stain your wood. Top off with sealer and then do your top coats.
I do this all the time with Padauk , it also has canyons in it.
 
I've tried that saw dust method with mixed results. It took a lot more applications than I was expecting, to really fill the pores that is. One aspect of pore filling that is often overlooked is how it blends with the actual wood and whether it gives a natural look. I find the clear fillers often give the better looking results. If you look closely at your picture you will find that the deeper pores look darker in colour than the shallow pores. Many fillers end up making all the pores the exact same colour. I'm not saying it looks bad, just that it doesn't look as natural as using a water clear filler. Shellac looks the part but takes a long time to fill pores. I've never used CA or Epoxy but I can see those working well, at least in terms of colour. Recently I've been using just clear oil varnish, applied very liberally. I've also tried this with Tru oil but you really need to forget about the usual method of application. Tru oil is a bit on the thin side, you really have to be very excessive with it. It also takes 4 or 5 applications, although each application is easy and quick enough to put on. I just use my fingers to work it into the pores. Oil can really darken the timber so it's best to do a test piece. If you don't like the result you can apply a couple of quick coats of shellac first.
 
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What I've noticed about Tru-oil and shellac is that they both continue to shrink for a very long time. I did one uke with the Tru-oil pore filler and then Tru-oil. It was perfectly flat when I finished it. Months later, the material has shrunk back into the pores. I guess I should pin that on the pore filler more than the Tru-oil itself, but it does make me wonder how long it takes for the finish itself to stabilize. I know you have done a lot of work with shellac, Sequoia; don't you find it takes a long time to finish shrinking and hardening? Seems like you would need a very long finishing schedule to be sure your pores wouldn't reappear over time. I haven't tried epoxy, but Allen certainly uses it to great effect. I find the Starbond CA works really well on deep pores, though it is pretty fumey to work with.

Nelson
 
I have had some success with shellac and pumice powder (rottenstone). Sprinkle pumice on the surface, dip a cloth in shellac and using a circular motion, rub the pumice and shellac into the wood so that it forms a slurry. You can add a bit of sawdust to bulk it up. Wipe off across the grain. Let dry. Repeat. Let dry. Repeat until satisfied. It does shrink back a bit but it's pretty low tech and the fumes are not unpleasant
Miguel
 
I seem to get the best results with zpoxy. I have tried the clear water based fillers and had no luck especially with pores that size. You can always lay the epoxy over those areas a little thick and srape it back.
 
Ones that deep are going to benefit from an epoxy fill. Even then it'd going to take at least 3 sessions.

If you go with something like a shellac / dust or pumice fill, the potential for sink back or movement over time is probably going to leave you dissapointed.
 
Some before and after pictures of the attempted fill. Three sessions with sand-outs in between. Silver bullet? No. But this is a pretty extreme case. Only partial fills. I'm going to continue with a waterbased clear filler and then finish out with shellac... Yes, in this case zpoxy is probably the way to go and is shinkage going to be an issue down the line. Quite possibly... Onward! Into the fog!

Before

DSCN7250-001.jpg

After

DSCN7300.jpg
 
Eye see progress! Perhaps pernicious patience and application of the same will succeed!
 
Allen said:
Ones that deep are going to benefit from an epoxy fill. Even then it'd going to take at least 3 sessions.

If you go with something like a shellac / dust or pumice fill, the potential for sink back or movement over time is probably going to leave you dissapointed.
Click to expand...

Yes, and yes.
No grain filler is ever a one application deal. Its min 2 applications but 3 or 4 are totally normal....so we should all just get used to the norm :)
 
Zpoxy or something thick would be needed for those bigger crevices. I've used Tru-Oil in the past, but would like to use water base finish with maybe Aqua Coat for general filling.

https://images-na.ssl-images-amazon.com/images/I/51674HKeJZL.jpg

I've heard good reports on Aqua Coat Clear Wood Grain Filler, and have it in my saved cart to try. Any negative experiences?
 
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I've only done test panels with Aqua Coat. When applied to wood that has been thinned down to what we would use for ukulele bodies, the water content curls the panels quite a bit. This happens even if the wood is first coated with shellac. They do mostly flatten out when it dries but usually not entirely. This has deterred me from using it on an instrument. It does dry quickly and is easily scraped and sanded. I'd be very interested in hearing about experiences that others have had.
 
Rrgramps said:
Zpoxy or something thick would be needed for those bigger crevices. I've used Tru-Oil in the past, but would like to use water base finish with maybe Aqua Coat for general filling.

https://images-na.ssl-images-amazon.com/images/I/51674HKeJZL.jpg

I've heard good reports on Aqua Coat Clear Wood Grain Filler, and have it in my saved cart to try. Any negative experiences?
Click to expand...

Complete waste of money for me. I didn't like the smell, optically it isn't that great, it takes 3 or 4 applications. Like many things, it will fill pores, just nothing to write home about. At least Tru Oil will pop the grain.
 
Michael N. said:
At least Tru Oil will pop the grain.
Click to expand...

True enough! This claro tenor was done with nothing but Tru-Oil. It hasn't yet been buffed but is looking pretty good anyway. Tru-Oil can be used to pore fill by diluting it with mineral spirits and wet sanding to produce a slurry that fills the pores. Claro has big pores but it works out fine. Start with maybe 220 and work up to about 800. The number of coats and the grits used depends upon the hardness and porosity of the wood. Once the surface is smooth, subsequent coats can be laid down without sanding to build thickness. Wet sand with fine paper and water as necessary to keep it decently smooth during the build coats. Yes, I know that it will shrink back over time but most finishes do. Look at a fine instrument that has been sprayed with nitro and has had a couple of years to age gracefully.

There is something to be said for using a single product for the entire process. No need to worry about incompatibility of different products or to use shellac or something else as a tie coat.

30290083435_95a5701385_h.jpg


30290084515_2519aa4b63_h.jpg
 
Thanks! I wouldn't want to keep track of how many applications this takes. That might ruin it for me. :) Suffice it to say many. This really shouldn't deter anyone, though, because the actual amount of time that is devoted to a finish like this isn't too terrible. It comes in reasonably small segments of time spread out over a long period. If you have to get the finish done quickly, try something else. I usually do all of my finishing early in the morning and it gets to be an enjoyable routine. Drink coffee, read the mail, push each finish along, wake up tomorrow and do it again. Kind of like "Groundhog Day" without Andie MacDowell and Bill Murray.
 
saltytri said:
Kind of like "Groundhog Day" without Andie MacDowell and Bill Murray.
Click to expand...

Ha! Well put. I can relate. At least "Groundhog Day" finally ended. Sometimes with shellac I wonder if it is the movie with no end. But like you, I actually enjoy the process. Some Japanese Zen master once said that patience is the greatest of all virtues. He must have done instrument finishing. Patience is a very powerful thing.
 
Salty, sequoia said it; that does look great. Your effort and experience really show.
 
sequoia said:
Looking pretty good? It looks great! Lovely finish. (nice miters too)... How many coats did you do?
Click to expand...

I have only done a couple of full gloss finishes with Tru oil. I think you would be looking at around 20 minimum. I've heard of folk doing as many as 30. Somewhere between the two might be about right. It really is hard to say because much depends on the actual finish of the raw wood. Putting on that many bores me. With a brushed oil varnish I only have to do 4 or 5 coats, done.
 
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