Grain filling

[cjbfisher]

Thanks again for the replies from everyone.
My understanding is that the sealer is used to raise the grain of the timber, and to then sand those fibres down to a flat surface, but unless it is a very tight grained timber the sealer will do very little filling. Correct?
When sanding the sealer, should you really go back to bare timber? Wouldn't this be exposing more loose fibres that will lift with the next coat?
I have borrowed a French Polishing book from the local library, and am waiting for another by Bob Flexner to arrive. I'm sure the questions will continue.

[ian]

A bit more on grain filling ...

The following image is from https://www.popularwoodworking.com/articleindex/30921/



I'm guessing that the left half is what you are getting on the open grained New Guinea Rosewood, while the right side is what you would like?

[auscab]

Sealer is not for raising the grain . Water or water based products raise grain . If water based products are to be used on raw wood then raising and cutting back the raised grain should be done first .

[cjbfisher]

I'm guessing that the left half is what you are getting on the open grained New Guinea Rosewood, while the right side is what you would like?

Correct.

[ubeaut]

Sanding sealer was originally developed to fill the grain before spraying it with lacquer. The sealer was cheaper than the lacquer and formulated to help fill the grain whilst being easier to sand back without clogging the abrasive the way lacquer would. Thus saving time and money rather than filling up with grain filler or lacquer.

My U-Beaut Sanding Sealer is based on our White Shellac (Dewaxed) and rather than filling the grain it is designed to raise the grain that has been torn during the sanding process. This raised grain will stand up and go very brittle and will be easily removed not by sanding but with a wipe over the surface with your finest grit abrasive. Sanding will take you back beyond the wipe to raw timber and once again leave you with torn grain.

You can make a grain filler using U-Beauts White Shellac and adding a small amount of our pure Talcum Powder this will fill the pores of the timber in a couple of coats (may need more depending on the timber) and will not come out white in the pores. The talc helps to fill the grain and makes it easy to sand the shellac back without clogging the abrasive.

You can also make a brilliant grain filler that can be colour matched to the timber by making a thin gesso using our Hide Glue, water , Talc and either Water Dyes or universal tint.

Proprietary grain fillers can be good also. Wattyl Wood grain filler used to be my favourite that worked well every time. Haven't tried the Craftsman Grain Filler which as replaced it but if it's as good as their original wood grain filler it should be a goer.

Have a look at "A Polishers Handbook" for more info on grain filling and lots more.

Hope this is of some interest and help.

Cheers - Neil

[cjbfisher]

Thanks Neil.
I'm currently doing a bit of reading through several books that I have borrowed from our local library. There's a lot of information to digest, and I'll probably have forgotten a fair whack of it by the time I'm finished reading. I'm also struggling to comprehend some of it, as I'm more of a hands on type learner. I can read about it, but once I actually do it the understanding seems to develop.
One thing I haven't come across in my reading thus far is which type of finish is best used in which application. I'm sure I'll come across it at some stage.

[ubeaut]

My apologies for the blatant advertising above, but couldn't help myself.

A bit more on sanding sealer (at least the U-Beaut one) below:

Ever applied a surface coating like polyurethane, lacquer or shellac to a work piece sanded to around 240 grit (often sold as fine). If so, when it dried and you ran your hand over the finished surface, I'll bet it felt like someone had thrown a hand full of sand into the finish.

This gritty feeling is the torn grain from sanding being raised by the finish. It is even worse if the piece you coated was plywood, as so much of todays cheaper unfinished furniture is.

U-Beaut's Sanding Sealer was designed to raise that grain, make it brittle and then be sanded/wiped off with fine abrasive. by doing this you eliminate all those little nibs and get a smooth surface when you apply your finish.

My preferred way to use Sanding Sealer:

• Ideally use a Random Orbital Sander I have a Festool, but even the cheaper ones will do the job well.
• Sand through the grits 120, 180, 240, 340, 400, 600 and 800 then stop. With a good ROS it shouldn't take long.
• Moisten a clean soft lint free rag/cloth with Sanding Sealer. Not wringing wet.
• Wipe the SS over the entire surface of the work once, if needed add a little more to the rag to to cover larger area.
• Allow SS to dry at least an hour, more if needed. Timber should look and feel dry. If you have the time leave over night.
• Put a piece of 1200 grit onto ROS turn sander on to low speed (if variable speed) and basically wipe the grit over the surface. Don't scrub at it or work like you are sanding, it is basically one wipe over the surface and nothing more.
• When done get a clean lint free cloth and wipe the surface clean of any dust that may remain.
• Surface should feel silky smooth and will be ready for finishing.
• At this point you can add a water dye to the work if you wish to colour it. The dye will soak into the timber without raising the grain
• You can use a turpentine based stain over the SS but not alcohol based stain or dye as this could well make a mess of the surface especially if you intend to use shellac or any other alcohol based finish.
• Your surface is now ready to receive your preferred finish.

Personally I would finish with White Shellac or Hard Shellac for a horizontal surface that needs to be tough. Shellac will key into the pores of the timber where polyurethane needs a rough surface from sanding to key itself to.

WARNING:
Putting Poly over a very finely sanded surface could be a recipe for disaster down the track. I have seen a table top finished where the poly had completely delaminated into one massive bubble because it was applied to a very finely sanded surface and subjected to extreme heat. Hilariously horrific, terrible to repair and really costly.

Sorry for the ramble but hopefully it will be of help to some.

Cheers - Neil

[cjbfisher]

No need for apologies, Neil. After all, who would be more qualified than you to comment on your own products?
With regard to the shellac going out of date, what is the shelf life once mixed, and what happens once past the "use by" date?
If I was an irregular user, would I be better off buying flakes and mixing it as required?

[Cliff Rogers]

There should be a 'Best By' date on the label somewhere.

[cjbfisher]

Yes, there is a best by date on the bottle. Just wondering what the shelf life is leading up to that date, and what happens to the product once past that date.

[Cliff Rogers]

This is off the internet from 2 different places, it doesn't say what happens to it.
I had an old bottle of mixed shellac that I tried to turn into sanding sealer by diluting it with metho but it wouldn't set hard enough to sand without clogging the paper, I chucked it out.

The Hard Shellac is premixed & has an 18 month shelf life.

Once shellac flakes are mixed with alcohol, the mixture has a shelf life of no more than a year and a half.

[ubeaut]

Yes, there is a best by date on the bottle. Just wondering what the shelf life is leading up to that date, and what happens to the product once past that date.

Shelf life is until the best by date on the bottle.

White Shellac (dewaxed):
Best by date on the bottle means shelf life for polishing is 18 mths from the time it's put into the bottle until that date. Caution. Be aware that some sellers may not sell much of it so it could already be a year old or more when you buy it. Always check the best before date before handing over your hard earned.

After that date it will not fully harden on the surface. It will dry and feel hard but if you were to leave something heavy sitting on the surface for a few days, when you remove it there could well be an imprint from the base of that something, left in the surface of the finish.

If it is White Shellac you can mix it down 10 parts Industrial Methylated Spirits (either 95% or 100%. If it's off the shelf at the supermarket then it's all but useless) to 1 part white shellac and you should have sanding sealer that will work for years.

If it's been out of date for a few years toss it out.

If the White or Hard Shellac is a dark brown in the bottle and not a honey colour, it will be because it has been exposed to bright light. Ideally keep it and most of our polishes in an esky or somewhere else that is dark and has a bit of temperature control. We keep all our products in a refrigerated container that's pitch black inside and is kept at a constant temperature of around 12-13^oC.

Hard Shellac:
Hard shellac also has n 18 month shelf life. However because it is hardened with a melamine solution it appears to work well beyond it's shelf life. I have had reports of people using it 5 years after expiry date and still not having a problem with it.

My short answer for Hard Shellac is once it uses it's best by date..... Throw it out, get rid of it, dispose of it (thoughtfully) ditch it, chuck it.... and buy a new bottle.

Hope this is of some help.

Cheers - Neil

PS
For Cliff and others:
Only use the White Shellac (dewaxed) for sanding sealer if you use ordinary shells there is a wax component in the shellac that makes it not work well as a sealer and will clog your abrasive. The dewaxed White should work well and not clog abrasive. Hard Shellac won't work and will more than likely clog adrasives. Most other shellacs will be pretty much useless, unless the wax component has been removed.

However... For what it's worth, common old everyday waxy gold/brown shellac is really good at sealing pitch into pine and stopping it from leaching out.

[Cliff Rogers]

Beauty, thanks. I can't remember what is was.... just when out to the shed & looked, I have White & Hard on the shelf & the hard is at the front so I most likely used it.