Thread: Grain fillers

Good stuff, quick and easy:
AquaCoat Clear Grain Filler now available in Australia - Armstrong Lutherie

This stuff works well and stains can be used after application.
Sanding Sealer | Sealer For Open Grain Timber

With this stuff, do you apply it, then sand it away completely so what is left is only in deeper parts only? Any idea if it works with osmo poly x?

You mean Aqua Coat? I've just been using some this arvo on those quilted Blackbutt boards. They have quite a lot of cracks due to the intense quilting combined with the splitty nature of BB, and I have to say I'm not too keen on the effect of Aqua Coat on them. There's a bit of greenish tinge or darkening to it.

On medium to dark timbers - no problem at all. See this pic of a Blackwood table treated with aqua Coat.

Perhaps on something like a blonde Blue Spruce guitar sound board it would be different. Anyway, on blonde timber do some tests first.

To answer your question though: yes, sand it off and that leaves the pores all filled up, and small cracks too. I usually sand to 500, apply the AC, sand with 500 again, and then sand up to where I want to finish (often 4000). Today I did a second coat after sanding off with 500 because of the cracks.

The 475ml (?) jar lasts for a helluva long time (great coverage). On that table I'd have been lucky to use 70-80ml, and I'd had the jar in a drawer for about 3 years before I opened it to use.

Yes, you totally sand off the Feast Watson sanding sealer as well. It's designed to fill the timber pores to give you a totally smooth surface to apply your final finish to.

I haven't tried these others yet but I've taken to using thinned out old shellac to fill some grain and lift the looser grains for scraping off.

TimberMate mate!!

Here's a review:



A good comparison test of various fillers - both for defect & grain:

It depends on what finish I'm using.

If a finish can be applied in multiple coats (eg. DO or Shellac) I'll generally let them fill the grain themselves. Coat/sand/coat/sand until smooth, then finish as per usual.

If spraying an NC based finish, I'll use an NC sealer. Wipe on, sand off, spray.

Originally Posted by RossM

TimberMate mate!!

For finishes that don't really multi-coat well (most PolyU's IMO) I'll use Timbermate, diluting it about 1:1 with PVA so it smears easily. This'll take a bit longer to dry then straight Timbermate, but I like it. This mix isn't the best at filling larger holes, though! You do need to be very careful choosing the right colour for your timber; I'll often stain small amount of it myself, using an Ash or Poplar base colour pot of T/mate.

Personally I dislike using PolyU's, even more so on open-grained timbers, but sometimes I'm told "that's what I want" and the customer is always right. An idiot, perhaps, but a right idiot.

Timbermate. Hmmm.

I inherited some a while back, and used it to fill some cracks in my benchtop (recycled hardwood). They claim it doesn't shrink, and they are right - with an oil finish it expands, and continues to do so for some years afterwards (I can almost always feel ridges).

Currently looking for a filler for some cracks in Blackbutt. Tried Intergrain "Radiata" - too pale. Forced into Timbermate "Oak" which was also too pale BUT, most disturbingly, it must have been abrading the stainless steel putty knife because the timber got black stains everywhere, and I could see what looked like SS powder mixed in with the filler on the knife. This stain appeared to sand off the timber, but it would definitely affect the colour of the filler that goes into the cracks and grain.

Eventually settled on Intergrain "Cedar" which is about as close as I will get.

Timbermate has "Made in Australia" on it, Intergrain doesn't specify. They both come in IDENTICAL plastic jars, and the lid mechanism is identical as well. Timbermate is 250 grams and Intergrain is 180 grams (same size jar) but the volume isn't proportionately as small - that is, Timbermate appears to be slightly denser TM is 39% heavier but not 39% bigger volume). Timbermate jar was 100% full, Intergrain about 85-90%. Timbermate was cheaper for a larger volume.

They both the same consistency and at first appear to be the same product, and except the Intergrain didn't yield any black stain (with the same knife). If this stain or abraded steel or whatever it is hadn't appeared then I would have sworn they were identical products, except for the density difference (which I probably wouldn't have noticed except for researching this post).

They both worked well as a grain filler (like in Ross's first video posted), but I didn't add water - just as a by-product of filling so many cracks.

Originally Posted by FenceFurniture

Timbermate. Hmmm.

I inherited some a while back, and used it to fill some cracks in my benchtop (recycled hardwood). They claim it doesn't shrink, and they are right - with an oil finish it expands, and continues to do so for some years afterwards (I can almost always feel ridges).

I definitely don't recommend T/mate as a crack filler. No matter what they advertise. Coloured epoxy for this li'l black duck! (Or plain ol' Bondo if it'll be desecrated with a coat of paint.)

I've never noticed any expansion when used as a grain filler, but that doesn't mean it's not there to some degree. Then again, I've been mixing it with glue for a long time now, which may also have a mitigating effect.

To be clear, in this case I'm talking about cracks up to 1mm wide in the Blackbutt. In the case of the benchtop they were about the same actually.

I'm doing another 'speriment atm with some Ironbark which is clear and unblemished, and I needed to use some grain filler on it, so I thought I'd use the Timbermate again to illustrate what I meant by the black stains.

This is just not on, in my book:

IMG_5673.jpg

That darkest bit is the wad of filler that I scraped off the back of the putty knife.

What is it that we are grain filling?

For pine and MDF, Timbermate is my favourite. I've a can of Feast Watson, but we have had a bad experience with it that prejudices me against it (a disaster of a disaster. Biblical.)

The AquaCoat I've been meaning to try. FF is twisting my are for a GB of the stuff Luthiers swear by it.

I also use car bog if the thing is to be painted. Fannnntastic result.

A diluted shellac works amazingly well too. A light coat, sand and repeat gives a most impressive result. I used to use this for my boxes until I moved to.... Epoxy and PolyU !!!

A thin few coats of epoxy is magic. Luthiers do this for an outstanding finish and tone.

PolyU on my boxes is fabulous.

So many choices

FF, I've also experienced the black stuff when using TM.

The scraper must be SS, or it reacts with the metal quickly. I used to use a Stanley 1" chisel, but it blackened like crazy.

Using a cheap SS paint/putty scraper from the car store works without blackening.

It was SS. If it's not then it's a new variety of non rusting steel - I've had it for a dozen years or more, blemish free.