Sanding Sealer

[Steve Walkom]

I have often seen references to people using sanding sealer on their work. What does it do and in what circumstances is it used?

Thanks.

[RFNK]

It seals (and therefore protects) the timber. It fills the pores and hardens the fine ends of the grain so that when you sand it, the grain sands away smoothly. It provides an excellent base for finishes such as polyurethane, varnish, wax etc. I use Feast Watson sealer but there are plenty of other brands. When turning, I rub it on the work with a small piece of rag then turn on the lathe. I rub it into the turning work until perfectly smooth. Then I let it dry, sand while still on the lathe and then add whatever finish I want.

[Rod]

You will find that if you do not use sanding sealer that the first coat of your finish will raise the grain and then you have to sand off something that may be a lot harder than sanding sealer. Certainly on turned articles I find sanding sealer to be one of the keys to a really good finish. Its not that expensive, give it a go and see what you think.

Cheers, Rod

[Mal]

I use Mirotone sanding sealer. I rub it on with a rag with the lathe stopped then cut it back with either 600 or 1200 grit paper. It makes an excellent base for the final finish.

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Luv
Mal

[Lance]

I was using some Feast Watson sanding sealer just today on a red cedar book case I am building. It seems to work well, apparently the cedar will suck up the varnish if you don't seal it first.

The only problem is it clogs your sandpaper up REAL fast.

cheers,
Lance

[Shane Watson]

Really there is no need for sanding sealer at all. All polish's are there own sealers. The first coat of any product 'seals' the wood. The main advantage in using a sanding sealer is to make sanding easier. I use mirotones lacquer and also use the corresponding sanding sealer - but the only real difference between the two products chemically is that the sanding sealer contains talc to make sanding easier.
Lance I would think that if the sealer you are using is clogging up the paper rather quickly, then its not doing its job properly, it may be on old batch would explain it not fully curing - which is what sounds like is happening.
Actually if you guys havnt already, check this article out that found and posted in the finishing section.
http://www.woodshopnews.com/stories/finish/

Cheers




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Shane Watson..

Combine Love & Skill & You Can Expect A Masterpiece!

[RFNK]

I don't think that all polishes seal well at all. I've found that many waxes, oils, polishes etc. look great for the first 6-12 months but then go dull. The timber just dries out. Sanding sealer actually seals the timber, like a varnish or lacquer, and also forms a really good base for wax and polishes. I've never had any trouble with it clogging up sandpaper, probably because I always use it sparingly and really rub it into the wood. When I use it on turnings, I rub it in like a friction polish.

[MJ]

G'day RFNK

When you apply sanding sealer like a friction polish, how long do you need to wait to apply a finishing coat?

[ubeaut]

RFNK
Waxes etc on raw timber, will as you say dull off. That's OK they're supposed to dull off, when this happens it means it is time to apply a little more wax to the surface. This will help nourish the timber and keep the work in tip top condition. That is one of the reasons why your mother probably used to polish the furniture regularly. (If you are a baby boomer or older, you should remember the weekly ritual of polishing the furniture, before the advent of Mr Sheen)

Steve
I suggest that if you intend to use a sealer that you would probably be best with a very weak shellac solution 8-10 parts metho to a premixed shellac. (preferably dewaxed white shellac) This will raise the nap of the grain and make it stand up and become reasonably brittle. This can easily be sanded using a very fine grit (600-800 or even finer) then a wax can be applied. This will keep the shine a lot longer, as RFNK suggests but will also allow the timber to be nourished by subsequent applications of wax.

Too many woodturners use sanding sealer the wrong way, as a finish. IT IS NOT A FINISH just a means to an end. It fills the grain and in many instances hides a multitude of sins. Most top class woodturners wouldn't touch the stuff except for use on their lower quality production work which will end up being sprayed.

If you are using a friction polish like Shellawax Cream the use of a sanding sealer will hinder the final finish as it needs to be burned into the timber during application thus fusing itself into the wood rather than becoming a surface coating which is much easier to damage. Sealer will also dramatically hinder the application of most oils.

My 2 bobs worth.
Neil

[JackoH]

You must be patient with your finishing. Most experienced wood turners will tell you they spend more time finishing i.e. sanding than they do actually turning. I have a tin of sanding sealer which I have used only once. There is no substitute for very sharp tools for that final cut followed by careful sanding right down to 800 or 1000 grit followed by at least 2 applications of EEE, and then if you want it really shiny Shellawax Cream or liquid.
See you at Stand 18 at the WWW Show, Jeffs Shed, Melbourne at 11.00am. Friday Oct.27th and I will buy coffee for U ,and Beaut and .(This is not a paid commercial!)
John H.

[RFNK]

OK Neil, let's get a couple of things straight... Firstly, sanding sealer is NOT a finish, it just provides a really good base for various finishes. Not everyone actually enjoys re-polishing all their stuff every few months, or even every year! Sealer also helps to keep timber stable, I believe. Secondly, and I hope this doesn't hurt anyone too much, the chances of anyone who regularly reads this bulletin board NOT being a `baby boomer or older' would have to be very small, I reckon! In answer to the query above, I'm not sure how long you should really wait to add finish after putting sealer on like friction polish. It seems to dry straight away. I usually leave it an hour or two but that's probably not really necessary the way I use it. By the way, I also agree that sealer is not a substitute for fine sanding. Sharp tools, rub that bevel, sand to 300-400 really well, then use sealer, then use wax, danish oil, poly, boot polish, or whatever takes yer fancy ..........I reckon!

[Shane Watson]

Rick,

Sealer is, as Neil says, a Means to an end. From my experience sealers are a lacquer based product anyway. Thats why there is no need to continually 'Feed' the finish as you would with waxes and oils. But in reality even using a sealer and then polishing with a wax or oil, you still should reapply the wax or oil occassionally as because it hasn't been 'Fed' into the timber it will eventually ware off the piece leaving nothing but the sealer behind left to protect the timber..

Everybody has there own preferences in everything we do. There is no one way to do everything - especially when it comes to polishing.

Personally the only time I use a sealer is when I am finsihing with lacquer. Whenever I use waxes etc I either use themselfs as sealers or as Neil suggested a reduced mix of Shellac. Shellac is actually universally renowned as the best sealer - but how many people use it as such?

Baby Boomer? Might be too young to know what that means

Cheers



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Shane Watson..

Combine Love & Skill & You Can Expect A Masterpiece!