Filling grain of porous woods

G'Day Guys,
I am working on a piece in New Guinea Rosewood which has many large open pores which the Shellac will not fill. The books I have read say to use pumice powder to fill them but I've never seen pumice for sale and in any case it seems like a time consuming way to fill the pores.

Is there a short cut to filling grain for a first time french polish attempt? I tried it on a test piece of wood without any attempt to fill the pores and the shellac just sinks in or doesn't cover the holes at all, just like the books say it won't :B

Please give me your grain filling solutions.

Thanks

Coxy

Timbermate wood filler should be fine to use. Local Hardware stores will stock it. Timbermate comes in different shades so finding one to suit the rosewood won't be too difficult. You can also mix the timbermate to get the colour you want. Always test on a scrap piece first, it may take you a couple of tries to get the right colour as the timbermate wet will be different to it dry.

cheers
Wendy

Are you actually attempting french polish or just applying shellac? Too often people incorrectly use the terms interchangeably. Pumice is used in french polish because it has the ability, when used, to impart an extra glow as well as filling the grain.. If you are french polishing then you can get pumice powder from an art supplier, it is used to bulk out gesso.



Jerry

Everyone is entitled to my opinion

For a first attempt timbermate will be fine, but follow what Ruffly said, the filler will darken once you apply the shellac, so I would just reinforce the try it on a test piece first. On a recent box lid of New Guinea Rosewood I applied Tassie Oak filler and that seemed to match OK but still came up a touch darker than I would have liked (under shellac), but not enough to show.

Thanks for the reply Guys,
If this thread seems a bit out of place, that's because I thought I had posted it as a reply to the "Shellac - Tell me everything you know about it thread" I didn't know I had started a new one.

I am actually trying to French Polish, I have brushed on base coats then built up a body with a rubber and a bit of Lemon Oil for lubrication. It has gone reasonably well for a first time I thought, but it has many little holes in it from the pores of the wood.

So - Timbermate is the stuff to try is it? Is it hard to use, and does it remove any of the nice, varying light reflection that the Rosewood is so good for? That's one of the reasons I am using it and I don't want the filler to take any of that away.

Thanks again.

Coxy

well, timbermate is good and it's very easy to use. However, whenever you fill timber, you are going to lose the look of timber in the spot the filler is in. Filler is not clear, so.......

This makes me wonder if maybe further timber preparation might be needed before you start to french polish, i.e. sand/plane/scrape to the best, flattest and smoothest surface you can possibly do. The better the surface preparation, the less filler should be needed, which would mean more timber presence showing through the finish.

cheers
Wendy

Quote:

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Originally Posted by Yxoc

Thanks for the reply Guys,
If this thread seems a bit out of place, that's because I thought I had posted it as a reply to the "Shellac - Tell me everything you know about it thread" I didn't know I had started a new one.

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I moved it to a new thread as I thought you would get more suitable replies to what you're trying to achieve :2tsup:

Thanks DJ - It probably is a seperate subject.

Ruffly - I have done a lot of surface prep, But New Guinea Rosewood has lots of fairly large pores which move with the grain and leave holes of varying orientation on your prepared surface, it's not tearout or a scratched surface.

So would the timbermate just fill these holes? I'm not sure how it's used, do you paste it on and then sand again when it's dry?

Thanks
Coxy

Can you use a NC Sanding Sealer under shellac? :?

yes, that would be a good pore filler

Coxy,
You answered my question by saying you intend to french polish the rosewood, not just applying a shellac finish. So therefore you intend to produce a glass like blemish free finish. That is a big ask for a first attempt and IMHO a bit beyond the forum to give full instructions.

Normally the forum can answer questions and give advice, but it is hard to write an instruction manual for what is half art; half technique in short replies.

If you really want to learn french polishing, I suggest you hunt through the internet where there is a great deal of information (and misinformation) and/or buy a good book or DVD on the subject.

Jerry

Everyone is entitled to my opinion

One book suggestion: http://www.ubeaut.com.au/book.html :2tsup:


To be honest, Coxy, Buy some timbermate - ~$5? and give it a go. I'm finding it rather hard :rolleyes:to explain fully how timbermate will work and look. You'd understand much more quickly for yourself what I'm trying to say if you try it.

I'd hate to be recommending something to you that you use on your piece and end up hating it and me as it didn't end up looking the way you wanted it to.


cheers
Wendy

Guys,
Thanks for all of your advice. I'm not asking for you to tell me how to french polish - just some ways to fill the pores. I have the Ubeaut finishing book and I've read that and others and continue to read. I realise that My first attempts aren't going to be that great and so I have a couple of test pieces that I'm working on at the moment for research/practice. I'm at very early days at the moment but just wanted an easy solution to filling the pores so that I could just practice the polishing technique itself.

Wendy - Thanks for the Timbermate suggestion, I'll give a go.

Thanks again Guys

Coxy

Coxy,

One other method that helps fill the pores of the wood is to sand down after a couple of coats but do not dust the wood. Just get the rubber and work the wood shellac and abrasive dust into the pores with a circular action. Naturally I use the circular action on all coats until the last finish coats to drive any finish into the pores.


Jerry

Everyone is entitled to my opinion

I'm surprisd no one has mentioned wattyl wood filler here, its sole purpose is to do exactly what is being asked - to fill the grain holes.

Timber is made up of small cells when you cut or sand the surface you expose the inside of some of these cells. This is where the sap is and the dark colour of the grain is usually the hollows of the cells. If the timber is really soft the cells are large and the holes deep.

You have two alternatives, fill them with a paste and then sand the surface smooth and apply a coating or use some form of coating to fill up the holes.

If you apply any coating, shellac lacquer or what ever you put just as much on the high areas as in the holes so after a few coats there doesn't appear to be any progress.

When you french polish what you are doing is taking the shellac from the high areas resoftening them with solvent and pushing the soft shellac into the holes. Just like if you wer using a bulldozer to level ground. If you have more shellac on the surface than the depth of the grain holes moving the shellac around fills and levels the finish.

The only other way of doing this is to sand down which is what normal painters do to get a flat surface. French polishing does the same thing without the dust and as you are not shaving off the high spots and blowing away the dust you use less material and its ideal on shaped areas like carvings corners round or odd shapes in the furniture as you don't rub high spots through easily as you can when sanding.

Do a test on a bit of scrap, apply a few coats of shellac as you are trying to build up the thickness have them thick, brushing on helps rub some into the holes in the grain. Then dip your finger into the shellac and rub and melt the shellac Just do a small area (size of 10cent piece) and see if you can fill up the grain holes, you should be able too easily or you should see how much more material you need to get the holes filled.

Don't forget if the grain holes were 1mm deep (exaggeration) you need to put on shellac just over a half 1mm or more to allow you to fill up the holes with the shellac around the hole and leave some on the high spots to give you a flat shellac surface.

The idea of a wood filler is to speed up this filling by stuffing into the holes a thick fast drying filler. You normally pick a wood filler colour that is the dark colour of the timber. For pine that would be a light tan colour Mahogony a dark red/brown. If you use the oil based filler you will find it doesn't raise the grain as much as the water based ones.