Grain filling on edges and contours

[neilium]

It's my once-a-month serious question. Then it's back to my hanky-panky. Anyway:

I did three coats of grain filler (LMII water-based microbead) on a swamp ash/zebrawood-top tele body. Now that I'm finishing it in tru-oil, it's clear that the filler did it's job on the flat parts, but along the edge of the top and one spot on the edge on the swamp ash I'm getting an orange-skin texture where the grain isn't properly filled. Did I scrape too aggressively along the edge (I used a fake credit card)? Should I have thinned the filler?

I'm not going to go back and fix it; it merits an "oh well" at this point. It doesn't look bad to me. But, for future reference, what's the best approach for scraping wet filler on the contours?

 

[willyk]

Filler will shrink when it dries, despite manufacturers claims to the contrary. Repetition and patience is the only way to ensure the whole thing is filled. I thin the filler after the first application if I want to end up with a perfectly flat surface and allow progressively longer drying times between. The more you thin it the more it's gonna shrink and the longer it will take to dry.
You can possibly fix your problem as you go along by "wet sanding" your tru-oil coats into the body with 400 wet/dry paper. The wood dust/oil slurry formed by the paper will fill the holes to a certain extent and eventually the surface will become uniform, so all is not lost mate!
Hope this helps..... :icon_thumright:

 

[bpmorton777]

Im assuming you are using water to thin water-based grain filler? how much water?

Brian

 

[willyk]

I prefer an oil based filler Brian. I use the same stains to color the filler as I use to tint my clear coats. Also I feel more comfortable thinning the filler to a sloppy paste consistency with mineral turps and/or stain than I would with water based stuff. I might be wrong but I think with water based filler it could raise the grain, creating more work. :icon_scratch:

 

[jackthehack]

DON"T try to thin water based grain filler.... You're just defeating the purpose, and best case, you'll just have to apply more coats

Swamp Ash grain will absorb/shrink in more filler/lacquer/anything you apply more than any other wood I've worked with to date; never get in a hurry, make sure it's COMPLETE:Y dry; shrunk into the grain before going to what ever the next step is.

Haven't tried this with Tru-oil, but have in a lacquer finish more than once, should probably work... On a couple of lacquer finishes I've run into the situation in which either the finish winds up shrinking back into the grain LATER, OR due to one factor or another, you wind up with little flaws in the finish; one time I had a little place in the final lacquer coats about 1/8" of a circle that lfted up when doing final polishing. I've successfully applied more clear water based grain filler to even things back up and then, in my cases, shot more coats of gloss lacquer to get the final finish where it needed to be.

Don't have a lot of experience using Tru-oil, just finished by first one, but think you should be able to go back and do additional clear water based grain filler coats to even it out and then apply more Tru-oil on top to finish.

 

[neilium]

Appreciate the pointers! Will refer to this post for the the next one. This one goes in the "live and learn" column.

 

[bpmorton777]

my problem with the grain filler is that, even after 6 coats/sandbacks it still isnt filling up the grain all the way...it's in there but the grain isnt flat and level with the surface of the wood. I ave tried to slather it on and that doesnt help Ive also tried to warm up the can of grain filler and that didnt help either. CB had suggested to thin the grain filler as well. I havnt had the time in the last couple of days to work on it so I havnt done anything to it yet. Im using the stuff from stumac and the body is mahogany (from Warmoth).

Brian

 

[jackthehack]

my problem with the grain filler is that, even after 6 coats/sandbacks it still isnt filling up the grain all the way...it's in there but the grain isnt flat and level with the surface of the wood. I ave tried to slather it on and that doesnt help Ive also tried to warm up the can of grain filler and that didnt help either. CB had suggested to thin the grain filler as well. I havnt had the time in the last couple of days to work on it so I havnt done anything to it yet. Im using the stuff from stumac and the body is mahogany (from Warmoth).

Brian

Mahogany can be a real pain to fill; it's amazing how much stuff those tiny little pores can suck down, but there a few tricks:

1.) Part of the problem is that it is very easy to sand filler back OUT of the little pores, this is the reason CB always recommends using a sanding block; you can use the 3M sanding sponges or pads as well, but they get expensive in a hurry. DON'T try to sand back the filler with any form of power sander, you'll wind up pulling the filler out of the pores and have to do a lot more fills.
2.) Only use rather fine sandpaper; I use #220 then finish last coat(s) with another round of #320 or #400. Using finer paper will take longer to sand back, but if you use anything coarser than #220 you'll be pulling filler from the pores.
3.) If using colored filler; after 2-3 fills switch to clear. The color will remain in the pores, and you won't sand stuff back out the pores as easy if you're not trying to pull the black/brown/other color off the rest of the wood.
4.) Wait longer than you THINK necessary for the filler to dry. If it's summer and warm and I can leave the piece hanging out in the sun, at least 24 hours. More if it's humid. During winter, at least a couple or three days. Although the surface may appear dry to the touch, it still needs to shrink back into the pores and harden completely, or you wind up sanding it back out.

 

[bpmorton777]

Hey Jack

I dont have any power sanding tools and have been using one of those rubber 3m sanding blocks. first coating was sanded back with 320 grit and all the rest have been with 400 grit sand paper..the good 3m stuff that CB suggests. Ive been letting this stuff dry for about a week each coating and doing both the work and letting it dry in the house so the temp dosnt go down much below 60F at night when the heater is off.

Ill have to order some of that clear grain filler I guess.

Brian

 

[jackthehack]

What color are you using? The black stains the rest of the wood and getting all that sanded back right invariably messes with the fill, which is why I wind p using clear for the final fiil(s). If you're where I think you are; slather the first coat of clear on a little thick, let that dry throughly, and one or two additional regular coats should finish it up. Filling mahogany takes a lot longer than shooting all the lacquer coats, usually, hnag in there.