French polishing

[Parlourman]

Hi all,

I am french polishing No.1 it's going ok - but I do have a couple of issues that I need help with:

I'm using Ubeaut Hard Shellac.

Sealing coat 30% shellac/70% meth

I filled grain with Timbermate.

Have done 5 coats of 50/50 shellac/meth.

In between have been wiping off oil with meth - and here's the first question......after wiping off I get real streaks. I'm using as little meth, and going as lightly as I can, but i'm still getting them, and they remain even after the next session of shellac...... assume I'm taking off the finish here?

photo 1.JPG (118.04 KiB) Viewed 24427 times

I'm still getting a really patchy finish. With swirls. I thought that after 5 or so coats i'd be building up by now? i'm also still getting colour on the rubber after doing the sides/back.........

photo 2.jpg (144.6 KiB) Viewed 24427 times

photo 3.jpg (106.44 KiB) Viewed 24427 times

I'm guessing the answer to both is that I haven't built up enough body yet? I'm really trying to keep the finish as light as possible......too light!!?

I have some rottenstone for polishing, when I get there - what oil is best to use with it?

Thanks peeps

Steve

[kiwigeo]

If you're getting colour off the rosewood on your pad then that does suggest to me that youre taking off alot of shellac when you spirit off the oil. It sounds like the pad is in contact with bare wood to be picking up the colour.

Hard to see exactly whats going on with your efforts but you may be applying too much shellac to the pad. After loading the pad it should leave a dotty imprint when you pad it on some paper. If you get a single blotch then the pad is too wet.

You're cutting the Hard Shellac 50% which means you're using roughly a 2lb cut for bodying....that's abut what I use.

What sort of oil are you using? How long are you waiting after each bodying session before spiriting off?

If you're down to bare wood then there's the risk of oil from bodying sessions getting into the wood. Once that happens you're going to have some real issues.

I use walnut oil which tends to blend with the shellac more than other oils. I find I don't need to do much in the way of spiriting off of residual oil. Ill do up to 5 bodying sessions and then do a quick spiriting off session. The finish lies for 2-3 days and then I cut back with wet and dry lubricated with walnut oil. After wiping off the oil I find I don't need much oil on the pad for subsequent bodying sessions.

Rob is a FP guru and I'm sure he'll have some words of wisdom for you.

I notice you're in Adelaide. I'm around for the next few weeks so feel free to drop me a line and pop up for a visit.

Cheers Martin

[jeffhigh]

U-Beaut recommend mineral oil for FP with their hard shellac and that is what I use.
I don't wipe off the oil between sessions

[Parlourman]

Thanks.

Martin - you are certainly right amount one thing - I'm using too much shellac - way too much, and have been relying on that amount to slide the rubber around as opposed to the oil. In fact - i'm using such a small amount of oil that there is probably hardly any to wipe off.

My only thought on that is that surely that would lead to heavier coats as opposed to lighter ones?

I've been using olive oil up till now. But thanks Jeff - I'll pick up mineral (paraffin?) oil today.

I don't think I'm getting down to bare wood during the sessions -but then again I can't explain the colour on the pad. I'm leaving it at least 8 - 10 hours before wiping off.

I'll try again with a reduced amount on the pad - and using paraffin oil - and i'll let you know how I go.

Thanks for your help, and yes Martin, I'm down at Aldinga beach, would be good to catch up at some point. Likewise I have a good set of machines in the shop if you ever needed resawing/machining etc

Steve

[jeffhigh]

Hey Steve, I really like the look of your furniture projects.

I am no expert on FP only just gradually getting better but I'll add a few more comments
I've been wiping Shellac on things for 20 years, FP a guitar is very different

Generally I will build a bit of thickness first by wiping on a few wet coats with the grain, just wiped on not worked, no oil, come back in 20 minutes put on another etc. this will cover the bare wood quickly and start giving you some build.

Once that is done I start the FP and stop thinking in terms of "coats" but in terms of "sessions"
A wet pad will not deposit more shellac on the surface during this process it will just make the surface soft and more prone to catches and streaks. I tend to just add a few drops to the pad with an eyedropper every minute or so as needed.
I do like the mineral oil (I am using johnsons baby oil) it is low viscosity, non drying so it does not get gummy if left on after a session.
I also like microfibre cleaning cloths as a pad cover.
cheers
Jeff

[matthew]

I must admit have not had a lot of luck french polishing with hard shellac. I had the same problem when trying to spirit off, streaks and ended up dragging off colour.

However, it brushes really well and if you add a little spike oil and/or thin with isopropanol to slow evaporation, (i thin approx 50/50) and use a nice big soft filbert brush, you can get a really nice finish. You need a good quick brush technique though. If you build enough clear coats on top of your colour coats, and let dry properly, then you should be able to cut back with fine w&d with turps as a lubricant, and french polish the final top coat. Need a nice dry day for FP-ing though. In Sydney lately its been way too humid lately.

[kiwigeo]

To my knowledge nobody has answered the question as to how hard shellac copes with repairs further down the track. Any comments from anyone?

[Tod Gilding]

Good Question ,,,,,and I don't Know The answer, But unless it CAN BE reasonably easily repaired ...Well then it shouldn't be considered as an alternative to shellac IMO

[Trevor Gore]

I use the Shines stuff rather than the U-beaut, but they're very similar. I've not had to do a touch up on an old finish yet (>5 years) but I've touched up after about 2 years. Light marks can be buffed out, dings can be drop filled much as you'd do with lacquer. Do the fill, leave it proud and ask the customer to come back in a couple of months for it to be levelled and buffed. If I was having to refinish a panel, I'd start by sanding with 600 then get the fad out. Well cured finish does not readily soften with metho (I know that because I've spilt metho on my kitchen bench which is finished with hard shellac) but if you sand it first it does soften up sufficiency to get good adhesion. I haven't had to do that on a guitar, yet, though.

[matthew]

I don't see a huge problem with repairs. You just need to accept that hard shellac is no longer going to act like shellac when it crosslinks. However, getting shellac to stick to it shouldn't be a problem ... shellac sticks to just about anything except silicone. Shellac based varnishes are routinely used in the violin world as the touch-up varnish of choice, even if the original finish is an oil based finish.

More of an unknown is how hard shellac stands up in the long, long term, whether the crosslinking affects its durability and transparency over a long time period. We just don't know this. But we do know that shellac does, over a long period, tend to crosslink naturally anyway under certain conditions. So hard shellac might just be accelerating the natural process.

[Kev3]

+1 to all the above comments.
Only other thought with colour coming off on the pad - could it be anything to do with the Timbermate used as fill rather than the timber itself? I've used that stuff, thought I'd cleaned up and could still dry wipe a fine powder off after drying.
Either way, if you're trying to build a base layer I wouldn't fuss with the oils and spiriting off etc to start.

[auscab]

Hi Steve,
Standing next to someone and watching and asking questions and being shown how to polish for half an hour would equal a month or two of reading all the different opinions you will find in books and on the internet. So do take up Martin on his offer would be the first thing I would suggest.

I don't use oil through the body building / grain filling stages at all.

To do it well without oil though you do need to get the feel of how much polish is leaving the rubber , when to go from straight passes to circles and figure eights.
When there is a lot coming out of a fresh rubber ,stick to straight with the grain , when it's not flowing out to much ,go to across the grain work.

I don't see why people who teach how to polish a guitar recommend such rubbers as the one you are using, the shape and style of it just looks to me that some one who does not know what they are doing is teaching. That's fine , it will work , just not as well as the real deal, it will take longer to polish the woodwork with such a rubber.
Possibly by bypassing the slightly tricky to learn stage of rubber rolling and getting started quickly is the reason.

I would be using one three or four times as big , longer with a point ,and the fabric rolled down the back like a spine , and would grab it by the sides , funnily enough ,pretty much the same as I hold and use the mouse on this computer ,except my three fingers to the right of the mouse don't point down at my desk but curl and point out the back , one reason is because a bit of force is required to push shellac sideways across the grain as the rubber is on its way to running low on shellac

With the grain full and a few good cut backs with 280 grit paper and a mix of linseed oil and mineral turps I would be going to thinner mixes with the shellac and then towards the end start using oil . This is pretty much what I do on all of the Antique furniture I work on and the furniture I build and on my one guitar it worked fine.

Rottenstone I have used with the oil and turps mix as well ,seemed ok. And I have seen it used in a bottle with water and a little detergent, shaken and then applied to a pad.

[Parlourman]

Thanks Rob - some great points. And thanks to everyone else too.

Martin - I'll PM you next week and pop up to see you - I need to bend someones ear about the Gore books too!............

I have now got a finish that I'm really happy with. I rubbed back (and in some areas there was a lot to rub back!) with wire wool, buffed with rottenstone, and put a smidge of ubeaut wax on the neck, sides and back. It's not the finish I thought I was going to get - but I'm pleased. I save the full gloss polish till the next one! - which is on its way now too.

So.......

I was definitely putting on too much shellac.

The colour on the rubber was the timbermate filler. The only saving grace on this was that I put a really good sealing coat on before the porefilling - so thankfully I was not close to going back to bare wood.

I haven't used the hard shellac before. On furniture I use flakes - and I have to say I think they are a little more forgiving.

Thanks again everyone............. oh, and I realise that the herringbone binding is "the wrong way round" - but I really liked it that way so I went for it!

cheers

Steve

[charangohabsburg]

oh, and I realise that the herringbone binding is "the wrong way round" - but I really liked it that way so I went for it!

Well done!
But who is claiming to tell how it is "the right way round"?


Sorry for getting a bit off-topic by insisting on a part of Matthew's comment:

But we do know that shellac does, over a long period, tend to crosslink naturally anyway under certain conditions.

Could you elaborate on what these "certain conditions" are? I guess that it may have to do with some people's observation that shellac flakes, stored over a long period of time will not dissolve well (or almost not at all), while others claim that their shellac flakes they bought over two decades ago still dissolve properly. Knowing more maybe could help to control shellac's behaviour before and after application.

[matthew]

probably heat ... UV ... the usual suspects

[kiwigeo]

Discussed here: http://www.aiccm.org.au/docs/Bulletin19 ... o1and2.PDF

[ChuckM]

It looks like you finally got a decent result, really nice looking btw, so this post is a little late.

It's important to note that French polish is not the same as just padding on shellac. The technique is very specific and the oil is the reason it works. FP technique layers the shellac on quite quickly but if there isn't enough oil on the pad it will tear off the previous layers very efficiently. This is where we usually get into deep trouble and give up on FP as being too hard. It really isn't once you make the required mental leap. I use walnut oil.

I was long under the impression that the oil was unnecessary and kept trying to use little or none of it. Big mistake. When there's enough on the pad/muneca/rubber/... the pad glides over the surface easily and it's very easy to apply more pressure. Just don't ever stop moving it. Somehow the shellac gets through all that oil (or joins with it) and gets layered onto the surface. If the pad looses too much oil it's easy to know as the friction increases instantly and you've just ripped out a patch of the old finish. Not a good feeling. The "spiriting" at the end of a session is useful to help level the swirls. I'm not sure it removes much oil, maybe it does, but it does level surface ridges. When done this way the build rate is truly impressive. Within minutes of ending a session it's possible to touch the surface without any stickiness.

It's also quite easy to use alcohol, pumice and muscle power to fill the pores. I'd been using a regular wood filler for decades but recently decided to try the pumice technique. I did a test on a block of Spanish cedar. About mid morning I applied about 3 coats of 1 lb cut shellac as a base. An hour later I did a pumice fill. An hour later I started the bulk layering (also with 1 lb cut shellac). I went back and refilled once and did two more bulk sessions over the course of the afternoon. By the end of the day it was level and ready for a final rub out, or would have been if I didn't mind some shrinkage over time. I'd heard about people who could FP a guitar in a day and I can see how it can be done if the stars are all aligned and you're on your game. That rivals the UV finishes some are using for speed.

I've read that you can FP UBeaut. I've never tried to, although I've brushed/padded it and it seemed OK. I'd be wary just because I've come to believe that a successful FP requires very newly mixed shellac. Too much time passed and shellac takes forever to dry. I've resorted to mixing shellac the day before using it in 8 or 12 oz batches.

The Milburn FP tutorial is worth it's weight in gold, or at least superblonde.

[Tod Gilding]

Great result Steve. This thread turned out to be very informative thanks to all for the input.

[Tod Gilding]

I was looking at the Milburn tute that Chuck mentions, they refer to a resin that is dissolved with alcohol called Copol and Sandarac to make a hard shellac, has anyone been down this path?

[kiwigeo]

I was looking at the Milburn tute that Chuck mentions, they refer to a resin that is dissolved with alcohol called Copol and Sandarac to make a hard shellac, has anyone been down this path?

Shellac without the additives is surprisingly durable....alot more durable than made out by many. 3 of my FP'ed acoustics are doing stage service with an all girl band over east. The finish on these guitars is standing up surprisingly well to a fairly hard life on the road.

[auscab]

I was looking at the Milburn tute that Chuck mentions, they refer to a resin that is dissolved with alcohol called Copol and Sandarac to make a hard shellac, has anyone been down this path?

I would like to be able to put up pictures of FP work on guitars for examples of what I get to see with FP but guitars are a hobby and keeping my head above water with business means sticking with the furniture while things are this tight.

From what I know of copal or sandarac or rosin, is that a lot of polishers used it to repolish true FP work from earlier times , which ingredient it exactly is I don't know . what I have seen is that it turns to rubbish after time and makes the piece impossible to repair with out stripping it all of and starting again. I just know it as a spirit varnish job.

Back when this was done the polishers could opt for a mix with varying amounts of additives , the ones that went for the quick fix with a lot of whatever? and a less shellac produced the hardest to repair now finishes .
And the ones who only added a little gave us polish work that can be repaired these days .

The good old work that was just shellac is beautiful to work on and revives in a fantastic way.

Here is some furniture examples , no strings attached

This Australian Red Cedar wardrobe was made about 1870 to 80 and grain filled and polished with shellac , for what ever reason it was restored possibly in the 1950s and the front was repolished with a spirit varnish while the sides were left with the original FP

There is a before and after pic of where I have done a swirl with the corner of my blunt thumbnail ,the brittle spirit varnish on the front is chalky brittle and lifts and marks , it's crap, the side which I think would have a small amount of the spirit varnish over the mainly original FP handles the same treatment much better

The Sofa table in front of the wardrobe is a job I have been working on ,made about 1815 to 20 its similar to the wardrobe in that it had been restored by repolishing the top and leaving the base with its original FP job untouched. The client was not happy with someones restoration of the colour of the re done top so I washed it of and re polished it. Its just 3 body jobs , no oil , with blonde and then one finishing go over with a little oil , it has been cut back for another go and will probably be waxed.

The good old Traditional FP job with just shellac stands up well and I think the only reason why polishers went with other methods was for the time they saved in polishing .
I had a mate , he's gone now unfortunately, but he worked in a polishing only workshop, all FP no spraying , and they did work for a lot of the trade in Melbourne , as well as stair cases and full FP rooms for the local mega rich .
After years of only using traditional FP I remember the day he started telling me of how an older polisher was teaching him how to mix and use a spirit varnish mix , he was so exited about how quick and easy it was to use ," It bodies so quickly and shines up so fast " were his words . I was saying to him "yeah but isn't it the same shit we are trying to fix years down the track with so much trouble"
"yeah! but so what " was the answer I got .
The quality job takes longer , and I don't trust additives .

[ChuckM]

I've tried both copal and sandarac, but honestly it was so long ago I couldn't begin to give any kind of analysis. I just remember that they took longer to dissolve than the shellac flakes did and that I wasn't that impressed, but I don't know beyond that. I wasn't aware of the less than stellar qualities of the spirit varnish. I did try the Behlen violin varnish, which has shellac, sandarac and gum mastic as ingredients, but the drying time was pretty long and it seemed to dry too soft to me, at least during the time I had with an instrument.

Good examples and story to illustrate the point. Thanks !

[auscab]

I was playing with the rosin version a while back trying to see if it was good for the revival of spirit varnish , after a friend suggested I try dissolving the rosin first in pure Turpentine then mix with the shellac and metho . It smelt the same as the old spirit varnish smells when a rubber is applied to it. It did not seem to revive the old polish so well though.

[matthew]

sandarac, copal, elemi, rosin etc are just materials that have different properties (hardness/resistance to heat & water/transparency/colour/flexibility/flow characteristics) to the shellac, so unless you know why you are adding them there's no point. There's no miracle additive that makes the perfect finish.

In the violin world, sandarac is commonly used in very thick C2H5OH solution to fill small cracks, as it is transparent and hard. But as a resin on its own, like rosin, it is brittle and scratches easily. copal is a very pale softer resin; both resist water better than shellac. Again, in the violin world, spirit varnishes are typically brushed on, not french polished. There is an art to brushing on a spirit varnish. It's not easy to start with.

I agree oil is pretty important with french polishing. I suspect most of the oil eventually ends up soaking into the muneca, rather than mixing with the shellac. Sometimes a very thin film is left on the surface than can be just wiped off when the shellac sets up. Shellite is good for this too.

[kiwigeo]

Steve popped up to my place today and we had an enjoyable chat and tour of my workshop followed by a leisurely lunch at the Stirling Pub. Steve brought his newly built Dreadie up and I must say the guitar looks very impressive in the flesh. Unfortunately like alot of us Steve is picking up defects and "issues" on his builds that either don't really exist or are minor things only the builder of the instrument would pick up