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Cellulose Sanding Sealer


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Sealer implies it seals the wood to stop subsequent overcoats of paint or varnish getting sucked into the wood. The wood is sealed.

Does that not do the same job as a pore filler or grain filler? -or is this just a physical levelling of the wood surface by filling the pores with a putty or slurry that then sets hard, as opposed to reducing the porosity of the wood to absorb less lacquer with a sealing primer?

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A 'sealer' coat can be ANY finish at all, it really only implies the first coat that goes on will seal the pores of the wood from 'breathing' moisture in and out (to some extent anyway, some seal better than others), and thusly, whatever the first coat is is the sealer coat, that can be sanding sealer, lacquer, shellac, poly, oil, whatever finish you choose. There is no specific finish that is designated as a 'sealer' finish per se, it simply refers to the first coat, whatever that may happen to be.

Pore FILLERS actually fill in and level the small depressions (pores) in the wood.

2 different things. B)

Does that not do the same job as a pore filler or grain filler? -or is this just a physical levelling of the wood surface by filling the pores with a putty or slurry that then sets hard, as opposed to reducing the porosity of the wood to absorb less lacquer with a sealing primer?

Yes, this is basically correct.

Think of it this way:

Sealer = first coat

Pore Filler = a material that will fill in the pores until level with the rest of the wood.

And to make it even more interesting, some pore fillers CAN act as sealers (CA glue and hide glue for instance), but most don't (water-based and oil-based fillers just fill, they don't seal)

And some sealers CAN act as pore fillers (CA glue again :D ), but most don't (sanding sealers, shellac, lacquer, oils,)

Well, if you wanted to shoot 20 coats of lacquer or shellac, then they would be filling and sealing at the same time. Poly the same thing, but less coats since it builds much thicker and quicker.

So a sealer CAN be a pore filler if you want it to be.

Confused enough yet? :D

Sanding sealers are sort of inherantly misleading by their name.

They are normally just to be used as the first coats, because since they have SOAP in them ( :D ), it makes it easier for you to sand the initial finish back to level, where you then switch to your regular finish, that's all a sanding sealer is for, they could call it Sanding Lacquer and that would really be a better descriptive term of what it actually does and what it's actually for, the 'sealer' part of the name is sort of misleading (a little anyway...) if it leads you to believe that that product is specifically designed as a sealer and nothing else is...which is completely false.

PS, sanding sealers are COMPLETELY UNNECESSARY no matter what anyone else tells you, they are for people who want things to be REAL EASY, I personally fine regular lacquer to be quite easy to sand back and never use that sanding sealer stuff, bogus product to me really... B)

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I have been using Minwax sanding sealer for a while and have good success with it.It is pretty much a lacquer with lots of solids in it.I just brush on(too thick to shoot) 2-3 coats and wetsand until all gloss has dissapeared.I have used this on top of colour coats and found it totally acceptable.It seems to accept Deft Nitro quite nicely.Maybe I have doing this all wrong but when using Ash or other open grained woods this seems to be the best way.Have I been doing this all wrong? Rich

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Drak, I see where you're coming from, but I'm going to have to stick my neck out and say that some sealers can really save time and effort. Like you said, it can make things "real easy," but that's certainly not a bad thing. I personally love stewmac's vinyl sealer. The reason for this being that it dries very, very quickly and thus cannot soak entirely into the wood. Thus, subsequent coats of whatever finish you should apply lay on top of the wood, where they belong, rather than being absorbed into the wood. Some woods will absorb more than others, so it's really a case by case basis. Anyhow, it's not essential, but I really like it.

I actually use the vinyl sealer much like a lot of people use shellac. The reason for this being that sometimes I have an application where I need to seal wood quickly(perhaps binding channels, or the binding itself before dying a top) but can't use shellac because apparently it doesn't respond very well to being covered in poly.

As for a filler, I'm partial to using epoxy. It creats less fumes than CA and can have a long working time.



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That's cool, I was specifically referring to the nitro-based sealer, as that's what was asked about in the title, but obviously there are more sealers out there, and good points made about them. B)

I had a gallon of vinyl sealer a few years back, never wound up using it for anything really.

I think it boils down to the fact that I never use something if I don't completely understand what it is, what it's made out of, and what effect it will have on whatever is underneath and over top of it (interactions), and I never really understood or 'bonded' I guess, with the vinyl sealer.

The nitro sealer tho, I (personally) really see no need to use, and the solids referred to earlier are indeed, the SOAP in it.

Call me a purist if you will, it's OK. :D:D

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