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UkulelesRcooL
04-30-2016, 04:12 PM
Just wondering... but let me give you a little info first... I used a pore fill method that Robbie Obrien uses where he uses a one pound cut of shellac with sawdust from a shaker of whatever wood you are wanting to pore fill, that way you keep your wood color. he shakes the dust on the wood then uses a cotton ball with the shellac on it and rubs the dust into the pores.. It drys very quickly and fills nicely. So I did that and I began to french polish over the pore fill.. and found out quickly that the french polish was taking out the pore fill..actually found out the next day when I looked at the instrument and wondered... where the heck is the is the fill????

So... Im wondering if it is possible to spray the pore fill with either sanding sealer or Nitrocellulose lacquer before the french polish so that the pore fill stays intact. Then french polish it.

I know the reason why the pores became unfilled as the french polish is pretty much the same method as the pore fill method except your using a 2 pound cut of shellac and a tad of oil but without the sawdust. Thus pulling out all that was filled..
Thanks for any comments...
Bud

Allen
04-30-2016, 09:01 PM
You're pulling out the pore fill because you are going too wet with the French Polish on the rubber. It's definitely a skill to learn.

If you are going to go with lacquer over the pore fill, then you might as well go all the way with the lacquer. It's never a good idea to mix finishes like you are suggesting. It will lead you down a path with all kinds of things that can and in most cases will go wrong.

UkulelesRcooL
05-01-2016, 06:31 AM
Thanks Allen....
I suggested that we spray it to begin with but my friend was set on the polish and I understand the desire... who doesnt like the look of french polish??.... Just trying to figure a way around that will speed things up as we are running out of time with this.. but
Im coming to the conclusion that that's just the way its going to be..
We have begun using the shellac as a pore fill without the sawdust and that seems to be working... Thank you for the advice on the application of the polish..
Ill pass that on and keep it in my own file for future reference..
One of the problems I will be encountering here in the climate I live in is the inability to spray in the winter, which is probably an issue for alot of people.. Were french polish would be the ticket..
As you have stated... it takes skill and there is a learning curve Im sure..

Bud

Beau Hannam Ukuleles
05-01-2016, 07:13 AM
You can spray nitro over french polish though.
The thinner the FP the better.

Michael N.
05-01-2016, 09:18 AM
You can fill the pores with shellac but it will take you a long time. Don't forget that over time these things shrink back and harden. You'll start to see little dimples where the pores are. The answer is more shellac/french polishing. Eventually it works. In terms of colour to the pores it's certainly a good filler, one of the best.
I'd carry on with the saw dust fill. I tried it but it took quite a few attempts before the pores were filled, that's true with a lot of pore fillers especially those that require minimum sanding.

Titchtheclown
05-01-2016, 09:24 AM
You can also spray shellac.

Allen
05-01-2016, 11:02 AM
Spraying shellac has quite a few problems when it comes to humidity. It will blush like you wouldn't believe if it's cool and damp. Also getting the mix just right with air pressure and technique I think is even more difficult than the traditional methods.

You might like to try brushing on several coats after your pore fill. 1 lb cut is good. Get a bit of build on there and then level sand that. Then apply with the pad. The trick with the brush is that its a bit like using the pad. It has to glide on and off, and DO NOT go over your last brush stroke even if you missed a spot. The finish is still thin and you will be coming back again and will pick any spots you might have missed the next time around.

Michael N.
05-01-2016, 12:07 PM
I brush shellac and only use the pad at the very end. Don't expect shellac to fill pores when using a brush, it won't happen. Well it might but you'll be into dozens of coats. If your pore fill hasn't quite filled the pores the pad will do a much faster job than the brush. If your pore filling is good then brushing on shellac is mighty quick. In fact it might be as fast as spraying.

Timbuck
05-01-2016, 12:27 PM
I own a 1930's Martin style O soprano ukulele ...I bought it to get measurements from..it's finished in FP and there are loads of pores visible ..it is still a great ukulele to look at and play..So why? is this a great problem today to obtain a ukulele that has a finish like you'd expect to see on a Rolls Royce Car.

Beau Hannam Ukuleles
05-01-2016, 03:08 PM
I brush shellac and only use the pad at the very end. Don't expect shellac to fill pores when using a brush, it won't happen. Well it might but you'll be into dozens of coats. If your pore fill hasn't quite filled the pores the pad will do a much faster job than the brush. If your pore filling is good then brushing on shellac is mighty quick. In fact it might be as fast as spraying.

Michael N.
Do you pore fill with pumice ???

Im doing a guitar and I have to finish it to look like a cello- this (the pics) is the best ive come up with so far- Amber shellac, with 3 different colours (in different ratios) of stew mac concentrated dye in it.
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At first i tried my usual method of rubbing dye straight into the figured wood (like in this headstock) 90775 but the cello maker pointed out something i've never noticed before- doing this locks in the figure- it no longer 'moves' when you tilt the wood various ways. It still looks good (if not great) but not anywhere near as beautiful as a cello/violin finish where the figure moves and sways as you till it.

This new shellac method attains this :)

Michael N.
05-02-2016, 12:20 AM
I no longer pore fill with pumice. I've tried many fillers. The filler that gives a more natural look to the wood is one that is clear, even the pumice method colours the pore. For the most part it's perfectly acceptable, just depends on how close you look at these things. The one I use on Walnut is the oil/sand fill. I use Danish oil that contains a resin. That method darkens the wood and the pores a lot. You also have to let it dry for a few days and cut it right back, otherwise whatever you put on top might not like it. I'm just testing out filling with hide glue that has been made water resistant. I'll see how that goes, it's too early to report. It's probably like filling with superglue or epoxy. I've never used those to fill pores but I can see how they would make for a good pore filler.

Yes, you have to be very careful with dyes applied directly to figured Maple. That Cello guy would be very aware of that. You tend to lose the lively figure, it stops 'dancing'. It's a very forced look. Violin makers (at least most of them) expose the Maple to UV light, mostly in a cabinet with UV strip lights. It takes at least 3 or 4 days to get a decent amount of colour. Some then apply a very subtle dye/stain, something like a strong tea solution. Too much and you lose the dancing figure, just keep it subtle. The rest is colour in the varnish itself. Most use some sort of natural pigment in the varnish. Strongly coloured shellac - seedlac, garnet or button. Then they might add things like dragons blood! and/or other resins/dyes. Alkanet is useful, it dissolves in both spirit and oil, gives a Purple but if used sparingly you can push things more towards Red. There are many others, including the synthetic stuff. To be honest the only way is to get scrap maple and try a load of different combinations until you are happy. It's a bit time consuming but it's also bit of fun. I once varnished a walnut guitar with seedlac and a good amount of alkanet. In the end it looked just like purple Indian rosewood. It was an incredibly rich colour but it was walnut! I didn't really want walnut to look like rosewood. Lovely colour, just the wrong thing for that instrument.
If you do the tests always keep notes of just what you are doing. In the past I've picked up a piece of wood lying around in the workshop that I've put some sort of coloured varnish on. Sometimes it looks really nice (things change over time) and I haven't got a clue what I actually used.
Hard to say without seeing it in person but the stewmac sample looks fine. If you can get some colour on the wood before applying the stewmac stuff it might look even better. Exposing the wood to UV is a foolproof method. You can do it outside but out of direct sunlight, watch it doesn't rain. It just takes time, maybe a week or so. Inside the workshop it could take a couple of months

Michael N.
05-02-2016, 12:28 AM
I own a 1930's Martin style O soprano ukulele ...I bought it to get measurements from..it's finished in FP and there are loads of pores visible ..it is still a great ukulele to look at and play..So why? is this a great problem today to obtain a ukulele that has a finish like you'd expect to see on a Rolls Royce Car.


It's not really a problem per se, it's just that the fashion is for billiard ball finishes. I've seen many instruments from the 19th century that were glossy but no pore fill. Personally I prefer pore fill glossy, or open pores but with a matte or semi gloss finish, that looks perfectly nice to my eyes.

Beau Hannam Ukuleles
05-02-2016, 05:48 AM
Yes, you have to be very careful with dyes applied directly to figured Maple. That Cello guy would be very aware of that. You tend to lose the lively figure, it stops 'dancing'. It's a very forced look. Violin makers (at least most of them) expose the Maple to UV light, mostly in a cabinet with UV strip lights. It takes at least 3 or 4 days to get a decent amount of colour. Some then apply a very subtle dye/stain, something like a strong tea solution. Too much and you lose the dancing figure, just keep it subtle. The rest is colour in the varnish itself. Most use some sort of natural pigment in the varnish. Strongly coloured shellac - seedlac, garnet or button. Then they might add things like dragons blood! and/or other resins/dyes. Alkanet is useful, it dissolves in both spirit and oil, gives a Purple but if used sparingly you can push things more towards Red. There are many others, including the synthetic stuff. To be honest the only way is to get scrap maple and try a load of different combinations until you are happy. It's a bit time consuming but it's also bit of fun.


Yar- the cello guy (Chris Dungey) has a nice UV box, but as his cellos sell for $60,000 he should have one!- we originally were talking about doing the first step of the cello on the guitar- ie- a Primer with UV, then sealer, then build coats then colour, then clear but im skipping the primer as the results might be different with the cello and guitar (every piece of wood comes out a different colour even if the solution is diluted the same.) Im sealing off the wood from the colour with ca glue- i tried clear shellac but if i got bleed through etc id be in trouble in regard to teh figure dance which i need if im to colour match.
Ive learnt alot about scrapping from all this- its the way to go!
I will also be bying some pigment (powder) to play with after this build is done- that seems like a better way to go in regard to refraction of colour through clear to give depth (im reading about this in the Padding book)

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This is the Cello Guitar build thread-
https://www.facebook.com/BeauHannamGuitarsandUkuleles/media_set?set=a.957422031013177.100002361680367&type=3

Michael N.
05-02-2016, 08:39 AM
I built an entire (well almost) guitar finishing it with a scraper. I sanded the back of the neck. It's mighty hard to get it perfectly flat and that billiard ball finish that people expect on a guitar. Just as well I made it for myself. It was Maple although I did put it in my UV cabinet. I finished it in clear shellac and just put a bit of wax on top. It would not have passed the commercial test but I really got to like that finish. Tactile, warm finish, nice to hold.
The ground coats that fiddle makers use can be . . . . virtually anything! Not quite but there's a lot of stuff they try, a huge amount. Some just use clear shellac though. It's another world, almost an entire job just in itself. I've played around a bit with this stuff but then I get a little bored and just use tried and trusted methods. I even made a few batches of oil varnish, which I will probably never do again. I do like the colour coats and messing around with different pigments.
I haven't got that Padding book but I know about it. You can make a UV cabinet for not very much. Mine just has 2 UV 2 ft strip lamps, BL 350's. It tans instruments and dries oil varnishes. Handy to have. May have cost 50 including the cabinet, which was just an old single wardrobe that I picked up for 5. Actually I think it's chipboard. . . it does the job though. Looks like you are in very safe hands.

sequoia
05-02-2016, 07:00 PM
. If you do the tests always keep notes of just what you are doing.

This is such good advice. I just wish I always followed it. How many times have I been deep in the weeds testing and thinking and testing and thinking and then find the way to produce just what I want, and then a month later when I try to reproduce it, I have no idea what it was I did! Therefore, I am forced to re-invent the wheel I re-invented all over again. Deep sigh. When experimenting with finishes keep notes...

As for pore filling, I'm all in on the Stew-Mac clear synthetic. However, it will NOT completely pore fill so it is no panacea. In the 3 steps forward, 1 step back dance it will give you a head start. Plus, it is much less hard than epoxy or CA so level sanding chores are reduced. What nobody talks about is how these different pore fillers effect the wood and ultimately the sound of the instrument. My humble opinion is that they significantly effect the sound by stiffening the wood. This is not necessarily a bad thing and maybe even a good thing, but it does change the response. Not really an issue with backs or sides, but on tops... an issue.

Michael N.
05-03-2016, 12:25 PM
Yes, I wished I followed it too! There's always next time.

My pore filling experiment hasn't gone too well. Takes far too many applications. Then I had the idea of putting pumice into the hide glue, mixing it and applying it to the wood with a credit card. That worked much better and up to now it hasn't shown any white pores, so the glue must be clearing the pumice. There is one downside (there always is), it doesn't do a great deal for the wood i.e. it doesn't pop the grain, in fact it makes it look rather bland. I'll try putting on a coat or two of shellac or oil varnish first, then apply this filler on top. The shellac or oil will pop the grain. Not sure what the heat of the glue will do to the shellac or oil, might be a little too hot for it. Worth trying as a test piece.