Thread: Pore filling prior to French polish

I never use pore filler before I French polish. This primarily because I have seen too many 1890s pieces that were pore filled with coloured plaster of Paris. With time, the colour fades away and leaves lots of small white speckles. Timbermate is a fine product, but who knows how long the colour will last? A good french polish will last well over a 100 years - will the colour of the filler still be same then?

I haven't used much Tas Oak - about to make some picture frames so will know more soon - but I doubt it needs filler. Yes, maybe a bit more work to polish without filler, but a better result - better clarity - without filler IMHO. I find this true even for very open-pored timbers like Australian Red Cedar.

Polishing a large table with Hard Shellac may be a challenge, especially now the warmer weather is here (at least in Qld). Be very careful to keep the rubber fairly dry, any wet edge marks show and set hard fast.

If you decide to pore fill I would sand back to the 800 after filling.

David

Isn't pore filling done using pumice when French Polishing or is this just one avenue used?

I've been resting Ubeaut's ubeaut book on polishing. and just trying to gather as much information as possible.

Thanks

Thanks X, I thought that might be the case. So in a word, no shortcuts to pore filling! As for the weather, spring hasn't arrived in Perth yet, but expecting nice weather this weekend! And yes, keeping the pad just a bit damp, I learnt the hard way, a wet pad was one of my many rookie mistakes.

Hi Lappa, yes I have a copy of the finisher's bible as well, it is a great resource! I found a youtube demo about FP by Fabians Tiny Workshop to be very useful as well.

Swifty,

i’ve had some success with Acqua Coat clear woodgrain filler. Got it in Australia from a luthiers’ supply store. Sorry, can’t remember which one but Mr Google will know.

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Brian

Originally Posted by Swifty

Hi Lappa, yes I have a copy of the finisher's bible as well, it is a great resource! I found a youtube demo about FP by Fabians Tiny Workshop to be very useful as well.

Thanks for the heads up on Fabian’s tiny workshop. Just watched the FP video. Highly informative and a great result.

Originally Posted by Xanthorrhoeas

I haven't used much Tas Oak - about to make some picture frames so will know more soon - but I doubt it needs filler. Yes, maybe a bit more work to polish without filler, but a better result - better clarity - without filler IMHO. I find this true even for very open-pored timbers like Australian Red Cedar.

the "issue" with Tas Oak is that it's almost always quarter sawn, whereas other cabinet timbers are typically flat sawn. I believe this makes a big difference when french polishing.

Yes, bulk produced Tas Oak must be quarter sawn and kiln dried (qs, kd) to be useable and stable. Back-sawn or flat sawn Tas Oak is a very active timber - warps like mad. In fact, I understand that Tas Oak was primarily a firewood timber until the 'qs, kd' technique was discovered. The exception was the pieces that had that superb fiddleback figure - cabinet makers were prepared to put up with the issues to get to use that figure, which can rival fiddleback Blackwood. There is quite a lot of the beautiful fiddleback Tas Oak furniture from the 1900-1920s that was sold as Blackwood (at least second hand, probably through ignorance rather than an attempt to deceive).

As I said, I have not French Polished Tas Oak, but will soon do so. It looks very close-grained to me. I will be very interested to hear from Swifty how he goes, and to see the photos of course.

David

Hi David, well I've stripped it back, cleaned it up, sanded to 800 and have done about 3 hrs of pore filling. Lots of pores to fill, at least another 6 hours I guess. Not surprising as the surface area is about 2 square meters. Did not use timbermate in the end, doing it the traditional way. The planks are indeed quarter sawn or not far off. (Riftsawn?)
Pore filling with pumice, alcohol and a small amount of hard shellac in the pad to bind everything. I will put up some piccies when it' closer to done.
Tas oak? Lots of houses made of that stuff in Hobart, including the weatherboards. I grew up in one of them.

I think the pore filling is just about done now. It wasn't as long as I thought it would be. First pic shows the table just stripped; then the second shows after completion of the pore filling. The third photo is a close up of the pores, now choked with shellac, wood dust and pumice. It really is an open grained timber. The resulting surface looks good enough to start bodying up. I hope I don't mess it up!

Luthiers have convinced me to use many new ways to fill and prepare surfaces for pretty hard use.

Aquacoat is one of those: https://www.youtube.com/watch?v=3sE9JewE2pc

Wow Swifty! That is looking great. Not a bad shine up already and it’s onlt filled. Looking forward to seeing the finished product.

Yes, looks great!

My father-in-law was trained as a cabinet maker in Austria and he said that they had to polish with metho and pumice for a couple of days before they were allowed to use any shellac. They added dry powder colouring to the pumice for the darker timbers like Mahogany. Unfortunately, with time some of those colours fade and leave little white spots through the timber.

Because Tas Oak is such a light coloured timber the pumice should not cause any long-term issues and will certainly fill the grain and provide a finer surface finish too. I am surprised that Tas Oak is so open-grained; live and learn! I'm only making picture frames with it and the ones we already have (made professionally) were spray lacquer finished, but I will be using white shellac.

The Hard Shellac is great stuff - and is much more resistant than standard shellac but it is not completely impervious to heat and water. For example, if you leave a cold glass on the table for a few hours the condensation will pool at the base and can affect the finish. I made some coasters and gave them to my children, not realising they would leave them wet ... next thing ... "Dad, why are your coasters looking lousy?" So do make sure that spills etc. are wiped off fairly quickly or it may mark.

David

The job is finished now. Not perfect as the shellac sank somewhat into the pores, but it still looks OK. Just need to wait 3 weeks for the hard shellac to crosslink as Neil recommends. Also: following Neil's instructions to the letter as outlined in the Polishers Handbook is important, especially in the pore-filling and stiffing up stages. I have been tempted at other times to use other methods which did not work as well. So thanks Neil! I am still learning, I wanted to do a FP on a "real" project instead of just on a practise board, it was good fun! This time I had no swirls or ugly lines, so I am happy.