Finishing by hand...what to use?

kiwigeo · Post by **kiwigeo** » Thu Sep 18, 2008 8:42 am

Alfred J wrote:
Would silica powder mixed in with the egg white do the same job? I mention that only because I don't have any pumice, but I do have silica powder. Will try it out on an offcut.

This topic has been very helpful to me. finishing is not my strong point.

It depends on what exactly you're referring to as "silica powder". What exactly is the product? Pumice is basically silica dioxide (Si02). I use Behlens 4F grade pumice for my pumice pore filling.

gratay · Post by **gratay** » Thu Sep 18, 2008 9:18 am

what solvent do you guys use to clean down a guitar and to simulate a finish when looking for glue during final sanding.

Naptha is banned isn't it?
what else to use .....shellite, mineral spirit?

and what about inbetween coats ..do you wipe down with a solvent or just a clean rag? would you use a different product for an oil finish as opposed to shellac?

cheers grant

Bob Connor · Post by **Bob Connor** » Thu Sep 18, 2008 10:23 am

Naptha is lighter fluid Grant.

I buy cans of Zippo fluid.

kiwigeo · Post by **kiwigeo** » Thu Sep 18, 2008 10:24 am

Hi Grant,

1. I use shellite to clean wood prior to finishing after going over surface forst with a painters tack cloth. Shellite is also good for visualising look of wood under finish. I also use it to clean grease and oil off fret wire prior to a fret job.

2. In between French Polish sessions I give surface a quick wipe with a dedicated brush to remove any dust. No need to clean with any solvent.

Cheers Martin

James Mc · Post by **James Mc** » Thu Sep 18, 2008 3:01 pm

Hi Alfred
I never bother buying pumice, I just pick it up at the beach. To process it into powder just give it a rough crush then wash it out in a bucket. Take the floating pumice from the bucket, let it dry then grind it down to a powder (hammer in an old breakfast bowl does the trick). I put this powder in a jar and cap it with a couple of layers of nylon stocking held on by a rubber band. If you want a finer or coarser powder just change the nylon to a bit if fabric with a finer or coarser weave. If you shoot me your address I'd be happy to post you some.

Natural talcum powder (which is ground soap stone) can also be used as a pore filler. I've never tried it but have seen a few people using it when doing fine detail work while I was working for furniture restoration company.

I'll be interested to see how you go with your test using silica powder. I can't see any reason why you couldn't use any silica or rock based powder provided it is fine enough. Often you don't need anything other than wood dust, the advantage of using pumice etc is that it reduces shrinkage if the timber has large pores.

kiwigeo · Post by **kiwigeo** » Thu Sep 18, 2008 3:10 pm

James Mc wrote:Hi Alfred
I never bother buying pumice, I just pick it up at the beach. To process it into powder just give it a rough crush then wash it out in a bucket. Take the floating pumice from the bucket, let it dry then grind it down to a powder (hammer in an old breakfast bowl does the trick). I put this powder in a jar and cap it with a couple of layers of nylon stocking held on by a rubber band. If you want a finer or coarser powder just change the nylon to a bit if fabric with a finer or coarser weave. If you shoot me your address I'd be happy to post you some.

One way of doing it I guess but I prefer to buy a container of 4F pumice which will last me for years.

Just to be anal...the stuff youve got floating on top of your bucket isnt pumice. Pumice is by definition a volcanic rock while the quartz grains you scoop up on the beach are of predominantly fluvial origin. Sorry couldnt resist...I'm a Geologist.

Paul B · Post by **Paul B** » Thu Sep 18, 2008 3:30 pm

FYI: Shellite is Naptha, aka Coleman stove fuel, aka Zippo lighter fluid (the Zippo stuff isn't as pure IIRC). Took me a while to find that out. There was a faq somewhere on the web that gave local names for all these different solvents. I was happy when I found that out, all these yanks talking about some strange crap called Naptha...

Bob, you'd be better off going down to mitre10 and getting some shellite instead of the lighter fluid, you'll save a bunch.

kiwigeo · Post by **kiwigeo** » Thu Sep 18, 2008 3:37 pm

Paul,

I recall a thread in OLF or even in here where I was asking about sourcing naptha here in Oz. Shellite was identified as the nearest thing. I get my Shellite from my local Mitre 10. Unfortunately they dont put exactly what Shellite is on the outside of the bottles.

Okay heres one thread on the subject from the Ubeaut forums. Seems like theres still confusion as to what exactly Shellite is.

http://www.woodworkforums.ubeaut.com.au ... ght=naptha

Paul B · Post by **Paul B** » Thu Sep 18, 2008 3:52 pm

http://en.wikipedia.org/wiki/Naphtha

Diggers shellite MSDS is listed in the Wikipedia entry. That's the stuff you'll get from Mitre10. They all are a little bit different, but they are all Napthas. Close enough for our needs, and the Diggers stuff is less than $5/L.

Craig · Post by **Craig** » Thu Sep 18, 2008 3:53 pm

Just a word to those using Tru oil . I have found it reacts when using it over Zpoxy Finishing Resin. There is a thread on the OLF at the moment covering this. Tiny crumbs appear on the finish . I have micromeshed them off , and it's seems to have finally stabilized .I haven't tried the Tru oil sealer but now see it as a must.

Also, Tru oil isn't the safe /easy type finish it appears to be . Read the pack regarding Cancer Warning !!! With my Chemotherapy now in progress I would advise all to stay clear ! Not that I can definatley attribute it to this product , but why take the chance ? The big " C " ain't fun !

Shellac is the safest stuff to go with ( and the best acoustically )

You can even eat the stuff !

sebastiaan56 · Post by **sebastiaan56** » Thu Sep 18, 2008 6:27 pm

And drink the solvent!

Paul B · Post by **Paul B** » Thu Sep 18, 2008 6:50 pm

Martin it might have been me on the OLF saying that Shellite is actually Naptha. It took me a long while to find Naptha in Oz, and that it was just good old Shellite (a brand name that originated with the Shell oil company).

When in doubt - like when they don't print the contents on the bottle, go to the website and get the MSDS, they have to list the contents in that doc. I should know as I written a few of them myself.

Diggers is the brand most available around here (at Bunnies and Mitre10 etc). Here's the MSDS...

http://www.diggersaust.com.au/files/Shellite.pdf

kiwigeo · Post by **kiwigeo** » Thu Sep 18, 2008 7:55 pm

Thanks Grant,

Ive printed out that MSDS to go on display in my workshop. I try and keep an MSDS handy for all potentially hazardous chemicals in my shop.

Shellite doesnt look like good stuff to get on your skin.....

Craig · Post by **Craig** » Thu Sep 18, 2008 10:27 pm

sebastiaan56 wrote:And drink the solvent!

And I thought I was the only one

gratay · Post by **gratay** » Sat Sep 20, 2008 2:12 pm

Has anyone ever tried the Minwax wipe-on poly as an acoustic guitar finish

any good
Cheers Grant

Alfred J · Post by **Alfred J** » Sat Sep 20, 2008 9:15 pm

kiwigeo wrote: It depends on what exactly you're referring to as "silica powder". What exactly is the product? Pumice is basically silica dioxide (Si02). I use Behlens 4F grade pumice for my pumice pore filling.

System three silica thickener from lmi is the stuff I ordered to thicken up Z epoxy. The label calls it "fumed silica" but that means nothing to me.

It would probably work OK. When mixed with Z epoxy the mix goes off clear or close enough to clear. I've also been able to thicken up water based filler with it.

Have been too busy the last few days to try it with egg white.

Alfred J · Post by **Alfred J** » Sat Sep 20, 2008 9:20 pm

James Mc wrote:Hi Alfred
I never bother buying pumice, I just pick it up at the beach. To process it into powder just give it a rough crush then wash it out in a bucket. Take the floating pumice from the bucket, let it dry then grind it down to a powder (hammer in an old breakfast bowl does the trick). I put this powder in a jar and cap it with a couple of layers of nylon stocking held on by a rubber band. If you want a finer or coarser powder just change the nylon to a bit if fabric with a finer or coarser weave. If you shoot me your address I'd be happy to post you some.
I'll be interested to see how you go with your test using silica powder.

I've picked up that very light, grayish looking 'rock' on the beach before, and yes, I had some vague idea that it was pumice or people call it that. Kiwigeo advises that it isn't pumice. Whatever it is, it obviously works. I live near the beach so will keep any eye out next time I go for a walk. Very kind of you to offer to post me some, but I'm an expat Aussie currently living in Japan - near the beach

This topic had turned into a goldmine of advice. Shellite = naptha (more or less). Egg white pore filler and 'pumice' you can get for free

Alfred J · Post by **Alfred J** » Sat Sep 20, 2008 9:31 pm

Craig wrote:Just a word to those using Tru oil . I have found it reacts when using it over Zpoxy Finishing Resin. There is a thread on the OLF at the moment covering this. Tiny crumbs appear on the finish . I have micromeshed them off , and it's seems to have finally stabilized .I haven't tried the Tru oil sealer but now see it as a must.

Also, Tru oil isn't the safe /easy type finish it appears to be . Read the pack regarding Cancer Warning !!! With my Chemotherapy now in progress I would advise all to stay clear ! Not that I can definatley attribute it to this product , but why take the chance ? The big " C " ain't fun !

Craig, all the best to you mate.
I sincerely hope the therapy progresses well. I'll take your warning to heart, use rubber gloves and a fan when working with tru oil.

The most recent neck, over Z epoxy, I padded on 3 coats of shellac as a sealer, and several coats of tru oil over that. (With previous instruments I was using water based fillers. )Taking care with prep - final sanding the bare wood with 0000 steel wool, and using very fine al oxide paper to level sand between coats, only 3 coats of shellac produced a beautiful finish without having to french polish. In fact its so good that my next guitar - for my own use, its now in the mold - I've decided to go with just several coats of ultra blond shellac applied with a pad. i.e. I'm going to finish the entire guitar that way.

Craig · Post by **Craig** » Sat Sep 20, 2008 10:28 pm

Thanks for that Alfred .
You say you just pad it on ( not french polishing )

Could you explain that technique ?

joel · Post by **joel** » Sat Sep 20, 2008 10:52 pm

How about Tung Oil? Would it work as a guitar finish? It's a penetrative oil finish, that can be easily thinned for thin coats. It's flexible enough not to craze, yet hard wearing enough to be used as a floor finish. It's more environmentally friendly than poly's, and it's food safe (provided you don't have a nut allergy). It's also easier to get than tru-oil.

Colin S · Post by **Colin S** » Sat Sep 20, 2008 11:32 pm

I've never had the slightest problem using tru-oil over z-poxy. It has always worked perfectly with no grains appearing on the surface, just a perfect smooth tru-oil surface.

Like any other finish it does need to be used properly, it's not a magic system. But, if the z-poxy is allowed to harden off properly, and the tru-oil is applied in thin coats and left to dry properly between coats then it builds beautifully and with no problem.

If you try and rush it, or use old product then there may be a problem, but that is operator interference rather than product incompatibility.

Colin

Kim · Post by **Kim** » Sun Sep 21, 2008 12:16 am

Colin S wrote: Like any other finish it does need to be used properly, it's not a magic system. But, if the z-poxy is allowed to harden off properly, and the tru-oil is applied in thin coats and left to dry properly between coats then it builds beautifully and with no problem.

If you try and rush it, or use old product then there may be a problem, but that is operator interference rather than product incompatibility.

Colin

Thanks Colin,

I suspected as much given the conflicting feedback I have been reading over the years from people who have used Tru-oil over the top of Zpoxy.

It would seem that when ever one group is having great success and another is having problems, yet both groups are using the same combination of products, it indicates that the latter has just not come to terms with the required process.

Cheers

Kim

Alfred J · Post by **Alfred J** » Sun Sep 21, 2008 10:04 pm

Craig wrote:Thanks for that Alfred .
You say you just pad it on ( not french polishing )

Could you explain that technique ?

Make a batch of one pound cut shellac by dividing a jar into quarters. Mark each 1/4 on the side of the jar with a felt pen. Fill the bottom quarter with dewaxed shellac flakes then fill the rest of the jar with methanol leaving a bit of space at the top so that you can shake up the contents after replacing the lid. It does have a shelf life, so I wouldn't make more than you can use in a couple of months. It works wonders as a general purpose sealer and as I've just discovered its possible to get a beautiful gloss finish from multiple coats.

I make the pad by cutting a square piece of soft absorbent fabric from a singlet and folding it to make a pad the size I want. After use it can be stored for re-use in an airtight container. The cloth from the singlets I have is lint free. That's important. (I can buy new singlets and have plenty so the wife hasn't complained.)
Wipe on thin coats. Let it dry then lightly sand with 0000 steel wool or very fine al oxide paper. I prefer 2000 grit. keep doing that and watch the gloss develop

Unfortunately it isn't a durable finish and I have never heard of anyone doing this commercially.

gratay · Post by **gratay** » Mon Sep 22, 2008 2:42 pm

Just wondering if anyone can recomend where to get micromesh sandpaper kits..
Australia or OS?

Cheers Grant

Kim · Post by **Kim** » Mon Sep 22, 2008 2:52 pm

I think I got my last order of 3 kits from ebay usa, I would probably have paid more for 1 sheet if I bought local.

That would be funny if it were not so close to the truth.

Cheers

Kim

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Finishing by hand...what to use?

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