PeterF
Established Member
I've never tried french polishing. It isn't the skill that bothers me - that can be learned - its the fact that normal shellac is not as durable as a lot of other finishes.mrpercysnodgrass":3ta76a6c said:
Royal lac finish
- Thread starter PeterF
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Shellac is a lot more durable than many think. I know that some folk seem to strip a Shellac finish but the same people tend to strip a lot of the finishes out there. It's just the nature of their sweat.
Shellac (nearly always French Polished) is put on extremely thin. It gives the impression that it's on the soft side and that it wears very rapidly. Shellac most certainly is not soft. You only have to take a shellac flake and try scratching it with a fingernail to realise that it's a pretty hard finish. The mistake that many people make is that they apply shellac to wood, let it dry and then do a scratch test. Unfortunately most of the time it's the wood underneath the finish that is taking the scratch, in other words they are compressing the wood. The other common mistake is to handle the finish after it's dried but before it's truly cured. Commonly they advise 3 to 4 weeks after application. Better is more like 8 weeks. Seems a long time but that wouldn't seem all that unusual to a Violin maker. Sometimes you simply have to put the instrument away to cure and start to work on the next batch. It's not extra work, just a longer waiting time. Finally you can all sorts of adjuncts to alter the nature of Shellac. I use a spirit varnish (basically Shellac with other resins) and brush it on. I probably end up with a slightly thicker finish but nothing like the thick plastic type coating that you see on many instruments.
Hard is not the same as tough though. Some of the more modern finishes are very hard but some cannot take the knocks. When they do scratch it tends to show and show a lot. They are brittle and cracks in the finish aren't at all uncommon.
Of course a lot depends on how you handle the instrument. I know steel strings tend to be handled roughly but I've no idea why. There are pick guards for the plectrum lot. The rest must be more like abuse.
Shellac (nearly always French Polished) is put on extremely thin. It gives the impression that it's on the soft side and that it wears very rapidly. Shellac most certainly is not soft. You only have to take a shellac flake and try scratching it with a fingernail to realise that it's a pretty hard finish. The mistake that many people make is that they apply shellac to wood, let it dry and then do a scratch test. Unfortunately most of the time it's the wood underneath the finish that is taking the scratch, in other words they are compressing the wood. The other common mistake is to handle the finish after it's dried but before it's truly cured. Commonly they advise 3 to 4 weeks after application. Better is more like 8 weeks. Seems a long time but that wouldn't seem all that unusual to a Violin maker. Sometimes you simply have to put the instrument away to cure and start to work on the next batch. It's not extra work, just a longer waiting time. Finally you can all sorts of adjuncts to alter the nature of Shellac. I use a spirit varnish (basically Shellac with other resins) and brush it on. I probably end up with a slightly thicker finish but nothing like the thick plastic type coating that you see on many instruments.
Hard is not the same as tough though. Some of the more modern finishes are very hard but some cannot take the knocks. When they do scratch it tends to show and show a lot. They are brittle and cracks in the finish aren't at all uncommon.
Of course a lot depends on how you handle the instrument. I know steel strings tend to be handled roughly but I've no idea why. There are pick guards for the plectrum lot. The rest must be more like abuse.
mrpercysnodgrass
Established Member
Mignal is right in what he says, shellac is a tough and durable finish if left to cure. It falls short if it comes into contact with solvents or water but that, as I said earlier, is easily restored which can't be said of lacquers. I french polished dining tables for family thirty years ago and the finish is still good on them. If a dining table can take thirty years of use with a shellac finish then I am sure a guitar can.
If you have no experience of french polishing you would be better off using a brushing polish, you will however need to invest in a good quality brush. A squirrel mop number 10 or 12 for around £30 will last you a lifetime if looked after. My one is twenty five years old and will see me out! http://www.frenchpolishes.com/acatalog/Brushes.html
You are then still left with the dilemma of which polish to use. The trouble with modified polishes is you will never know what they are modified with. I have used Mylands brushing polish and found it to be very good, a few coats then cut back and buffed, it gives a very glossy finish and is pretty tough. Morrells heat resistant polish if thinned with about 10% meths is also very good. Smith&Rodgers do a brushing polish which woodfinishman could advise you on. Kremer do a violin varnish using a recipe from the early eighteenth century http://www.kremer-pigmente.com/en/mediu ... 79760.html again I have not used this but Kremer products are second to none.
P.S. If you want to try some of the mylands and morrells polishes, I can send you a small sample of each for you to play with.
If you have no experience of french polishing you would be better off using a brushing polish, you will however need to invest in a good quality brush. A squirrel mop number 10 or 12 for around £30 will last you a lifetime if looked after. My one is twenty five years old and will see me out! http://www.frenchpolishes.com/acatalog/Brushes.html
You are then still left with the dilemma of which polish to use. The trouble with modified polishes is you will never know what they are modified with. I have used Mylands brushing polish and found it to be very good, a few coats then cut back and buffed, it gives a very glossy finish and is pretty tough. Morrells heat resistant polish if thinned with about 10% meths is also very good. Smith&Rodgers do a brushing polish which woodfinishman could advise you on. Kremer do a violin varnish using a recipe from the early eighteenth century http://www.kremer-pigmente.com/en/mediu ... 79760.html again I have not used this but Kremer products are second to none.
P.S. If you want to try some of the mylands and morrells polishes, I can send you a small sample of each for you to play with.
Actually Shellac isn't that vulnerable to water or alcohol. I've pooled water and a strong 8% Beer on a Shellac surface and left it for an hour (water overnight). Wiped off and there was zero damage. I've tried quite warm water as well, 50 centigrade. No damage. Anything much higher than that and it is likely to show damage though. I've yet to try pouring a Vodka or a Whisky on to a fully cured Shellac surface but it wouldn't surprise me if the effect is that of fairly minimal surface damage, unless you leave the stuff on for a long time.
Hake hair brushes are a very good but cheap alternative. Anything that is designed as a large watercolour paint brush might be a good candidate for brushing Shellac - thin watery Shellac.
I have a couple of very expensive brushes but these days I'm quite happy using a 2" Royal & Langnickel. You can buy them on Ebay or artist suppliers. They come in a set of 3 - 1, 2 & 3" very, very cheap. I use the Hake (I think it's Hake) - anyway it's a natural bristle, off white. They also do some that have synthetic 'Taklon'.
Some folk like the Taklon bristle but they aren't for me, even though the one I bought was around £15 for a 2" one. I much prefer the very cheap Hake brush.
The trick to brushing Shellac is to use it highly diluted. I actually use my own variation of the 1704 Violin varnish recipe.
Work quickly but confidently. You simply cannot brush like you would with Oil varnish or Paint. It's just a couple of strokes and move, slightly overlapping strokes. Don't be tempted to go back and correct missed areas or 'mistakes'. You'll only make things MUCH worse. Leave it. You will correct it with subsequent coats - they all average out in the end. I apply up to 16 or 18 coats, which may seem a huge amount but each coat only takes a couple of minutes to apply. It's probably something like 20 seconds on the back of a Guitar. All these coats are applied in no more than 3 days, in intervals of 2 hours or so. If you leave it far too long between coats they don't bond with each other, you start to see witness lines when it comes to rubbing down. When all the coats are complete you are left with a finish that stays soft for days, perhaps weeks. You can literally peel the finish off with a fingernail 4 or 5 days after the last coat. I leave it a full month and then rub down wet with 600 or 800G, finishing in straight lines. Then you have the option of going through all the grits and polishing to a full on gloss. I don't bother. I finish at 800G and do 6 to 8 very quick applications of dilute 'french polishing'. Actually it's just dilute polish done in deliberate straight lines, just a few passes per session. The next session a few hours later. The objective being to fill in the scratches from the 800G - and nothing more. To a certain extent you can control the amount of gloss. Go to glazing for a very highly reflective gloss. Again I don't bother. I tend to like a little touch of 'texture' in the finish, something from the cloth. Just enough so that it avoids that very hard glass like look - that so many seem to drool over. :roll:
The whole thing is left a further month to harden more.
Brushing Shellac/Spirit varnish is just as skilled as high quality French Polishing. I've being doing both for many, many years. It does take a bit of practice before it becomes more like second nature but you can get it to look just like a French Polished surface.
Hake hair brushes are a very good but cheap alternative. Anything that is designed as a large watercolour paint brush might be a good candidate for brushing Shellac - thin watery Shellac.
I have a couple of very expensive brushes but these days I'm quite happy using a 2" Royal & Langnickel. You can buy them on Ebay or artist suppliers. They come in a set of 3 - 1, 2 & 3" very, very cheap. I use the Hake (I think it's Hake) - anyway it's a natural bristle, off white. They also do some that have synthetic 'Taklon'.
Some folk like the Taklon bristle but they aren't for me, even though the one I bought was around £15 for a 2" one. I much prefer the very cheap Hake brush.
The trick to brushing Shellac is to use it highly diluted. I actually use my own variation of the 1704 Violin varnish recipe.
Work quickly but confidently. You simply cannot brush like you would with Oil varnish or Paint. It's just a couple of strokes and move, slightly overlapping strokes. Don't be tempted to go back and correct missed areas or 'mistakes'. You'll only make things MUCH worse. Leave it. You will correct it with subsequent coats - they all average out in the end. I apply up to 16 or 18 coats, which may seem a huge amount but each coat only takes a couple of minutes to apply. It's probably something like 20 seconds on the back of a Guitar. All these coats are applied in no more than 3 days, in intervals of 2 hours or so. If you leave it far too long between coats they don't bond with each other, you start to see witness lines when it comes to rubbing down. When all the coats are complete you are left with a finish that stays soft for days, perhaps weeks. You can literally peel the finish off with a fingernail 4 or 5 days after the last coat. I leave it a full month and then rub down wet with 600 or 800G, finishing in straight lines. Then you have the option of going through all the grits and polishing to a full on gloss. I don't bother. I finish at 800G and do 6 to 8 very quick applications of dilute 'french polishing'. Actually it's just dilute polish done in deliberate straight lines, just a few passes per session. The next session a few hours later. The objective being to fill in the scratches from the 800G - and nothing more. To a certain extent you can control the amount of gloss. Go to glazing for a very highly reflective gloss. Again I don't bother. I tend to like a little touch of 'texture' in the finish, something from the cloth. Just enough so that it avoids that very hard glass like look - that so many seem to drool over. :roll:
The whole thing is left a further month to harden more.
Brushing Shellac/Spirit varnish is just as skilled as high quality French Polishing. I've being doing both for many, many years. It does take a bit of practice before it becomes more like second nature but you can get it to look just like a French Polished surface.
Woodfinish Man
Established Member
Loving these posts on the merits of shellac and dispelling the myths.
Before PU Varnish it was the wooden floor finish of choice!
Before PU Varnish it was the wooden floor finish of choice!
Sorry to be resurrecting an ancient thread, but some 12 years later this product still seems unavailable in the UK. I'm still really interested in it though, although I agree with Mignal's comments that French polished shellac is a lot more durable than it is given credit for. However, the main reason I am posting is regarding Rustin's Plastic Coating, which got a bit of a roasting on this thread. I think the name puts people off, but it is just a 2 part clear lacquer. I know of at least 3 professional luthiers who use it exclusively and have had 3 handmade guitars and 1 mandolin finished in it, with excellent sound qualities to rival my Martin guitars finished in nitrocellulose, and guitars I have finished myself with French polished shellac. This is because it can indeed be applied in very thin coats. I no longer use it myself because it does not burn in like shellac and because it is unpleasant in use and I would advise users to use a fume respirator throughout. Guitar makers I have spoken to have been happy to use it in the open air!
