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Quick (and stupid) question on shellac sanding sealer >>

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OscarG

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I have a bubinga project, plan is to use shellac sanding sealer then black bison wax.

As per Custard's thread (where he compares waxes) I've sanded wood to 220, and will apply 2 coats of sanding sealer and sand 320 in between.

Just thinking though and sorry if this is really dumb question, but does it matter what direction you brush on the sealer? Should it be in same direction, with the grain or across the grain like a filler?

I've tried searching but can't find the answer to this.

Also if I don't have 320, does it matter if I sand between coats with 400?
 

ED65

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It shouldn't matter much but why not simply err on the side of caution and brush with the grain? Just like with sanding scratches if (any) brushmarks are aligned with the grain of the wood they'll be less noticeable.

If you have 400 by all means use that instead of 320.
 

OscarG

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Cheers!

Well i wondered if the sealer is designed to level the surface and like a grain filler applied across the grain?
 

Rorschach

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No it doesn't fill the grain. It helps stabilise the surface and limits absorption of other finishes to make them more even. Shellac is also like the worlds best primer, it's near universal in its compatibility.
 

ED65

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OscarG":3a807d4n said:
Well i wondered if the sealer is designed to level the surface and like a grain filler applied across the grain?
Much too thin for that. As Rorschach says sanding sealer is more a sealer as the name suggests. Without going into too much detail, any clear finish can actually be used to 'seal' the surface of wood, so technically the first coat of any finish does this. Commercial sanding sealers are made specifically for the purpose though and generally include an additive to improve sandability (typically zinc stearate, a waxy solid) which is why you have to be careful using them under certain finishes. And why in many cases you don't actually want to use them but instead rely on the first coat of the finish you're using anyway.

You can fill grain with shellac but you'd use straight shellac for this and may want to use a particularly heavy cut, 4lb or more. Even with that it's a pretty laborious process, requiring many coats in some cases, perhaps 8-12, and you should leave it to harden off for a good long time (weeks) before cutting back to flat.

So not the most efficient way to do it to say the least! You can fill grain in basically one day with a commercial grain/pore filler or a homemade equivalent, or as traditionally done using plaster of Paris used straight or coloured in various ways.
 

custard

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Bubinga is a fairly close grained timber, you'll get all the grain filling you need from a coat or two of sanding sealer. I doubt there'd be much of a difference applied across or with the grain, personally I'd always apply sanding sealer along the grain, but that's just a reflex rather than a considered judgement.
 

custard

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OscarG":3cjc4u6e said:
the application of sanding sealer made a massive improvement to my previous attempts at using a wax finish. I wish I had used it on previous projects!
Go back to the 1970's or 80's and sanding sealer plus wax was the go to finish for most hobbyists. But more recently it's fallen out fashion and you hardly hear about it any more.

I guess the result is a bit too glossy for modern tastes, or maybe it's not robust enough in a world where few people use coasters and place mats. That's a shame because sanding sealer/wax is a super reliable and simple finishing technique, glossier results are long overdue a comeback, and there's a lot to be said for finishes that although they may get scuffed are still easy to repair or re-finish.
 

OscarG

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Yeah I can see why, it's a really nice finish and if a muppet like me can do it, anyone can! I'm a bit like SunnyBob in that I prefer the glossier finishes.

I made this iphone stander thing, it's in the "projects" section, very happy with but as the phone warms up from charging it makes the phone smell like a wax candle! I guess for this application wax probably wasn't the smartest idea.. it does look nice...for now!

I forgot to say, I also heeded your advice of doing most of sanding with 80 grit (previously I'd have very quickly reached for the 320), it was a long time before I went to 120 and the rest, that made a big difference too.
 
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