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BigFryMan

Your finish process - to french polish or not to french polish?

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Hi all,

Just put the last coat of varnish on violin #2.

Do you do any finishing on your last coat of varnish after it is dry?

I got a few little specs of dust/hair in my last coat of oil varnish (it's about 2 days dry now, will probably be a week or so till properly hardened up as I'm running out of natural UV) and I'd love it if they weren't a feature of the final product.

On previous coats I've been giving a light sand with 600 grit wet and dry, then burnishing with a soft soft-brite pad and then a cotton rag. That seemed enough to sort out most blemishes and any unevenness. I'm not sure that I want to do that on a final coat.

I thought that maybe a french polish might be the best way to finish up so I ordered some fine powdered pumicestone. Last night I was reading Roger Hargrave's double bass build and he said that unless he was antiquing, he doesn't french polish his instruments so it's made me think twice. That and I've never french polished before so I'd need to learn and practice first.

What do you do after your last coat? Or do you just get it 100% perfect off the fingers/brush? ;)

Thanks again for all the advise, I really appreciate the collective ideas/wisdom of everyone here.

Josh

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Get some UVA tubes.
Learn to use a varnish brush and you won't be farting about with varnish on your hands. 
Put one drop of cobalt or other drier in each coat, helps.  

French polishing really has nothing to do with violin making, in it's pure form it's done with a pad on a flat table top or similar, 
building up coats of lac then cutting back etc. 

Shellac doesn't really stick well to a new oil varnish, so what's the point when doing a straight finish. 

If you're doing an 'exact copy', (something that might resemble a particular instrument when seen from 10 feet away), 
then sure, use shellac and retouch the bushings and edges. 

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You definitely want to build a UV box.  Check out 1rpm disco ball motors.  Blacklight tubes work fine. 

Micro-mesh sheets are easy to use and leave a nice satin finish.  2400 works for me. 

If you want a glossy finish you could try Renaissance Wax.  It's much easier than french polishing.

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You definitely want to build a UV box.  Check out 1rpm disco ball motors.  Blacklight tubes work fine. 

Micro-mesh sheets are easy to use and leave a nice satin finish.  2400 works for me. 

If you want a glossy finish you could try Renaissance Wax.  It's much easier than french polishing.

Thanks DoorMouse, I will check out the micro-mesh sheets. Yes I had a UV cupboard for the last violin, but haven't gotten around to building one this around.

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Thanks DoorMouse, I will check out the micro-mesh sheets. Yes I had a UV cupboard for the last violin, but haven't gotten around to building one this around.

For a quick solution, 2nd hand facial tanning units are effective, cheap, and can turn any spare cupboard space into a makeshift UV box.

You have to modify them a bit to bypass the timer.

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Re-UVA box, instead use the corner of a small room if you have one. 
More room for tubes and Cellos, more ventilation if you have a window. 
Remember that oil varnish takes ages to dry fully.

Buy quality new UVA tubes, not old ones from a used sun bed because they lose
their effectiveness after 6 months hard use. The Philips ones with built in reflectors are very good, 
not cheap but last twice as long as some others. 

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pumice, rottenstone and rubbing oil to smooth down the final coat, with the grain, no swirls, swirling is for dervishes, so sayeth the mighty Joe :lol:

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pumice, rottenstone and rubbing oil to smooth down the final coat, with the grain, no swirls, swirling is for dervishes, so sayeth the mighty Joe :lol:

Hahaha thanks Jezzupe, pumice and micromesh I have on the way, but what is rubbing oil? I was wondering what oil to use with the pumice, I have linseed and olive.

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BFM, when you rub out your final coat are you able to do so without losing texture on the belly?  A problem I've been having on cut-offs I'm using for practice.


 


Thanks,


Jim


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BFM, when you rub out your final coat are you able to do so without losing texture on the belly?  A problem I've been having on cut-offs I'm using for practice.

 

Thanks,

Jim

 

I'll let you know when I attempt!

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Definitely rub out the final coat to remove any nibs. Backed abrasives will reduce or remove texture, powder abrasives less so. Gloss can be adjusted by using different types of abrasive powders in different grits and with different backing material. I currently use 3/0 pumice on leather for aggressive smoothing, nappy side down on the top to maintain the texture. Then finer pumice or Tripoli on cheese cloth  to adjust the gloss. You want to wait several weeks before final polish on oil varnish as they are still soft for a while. Removing the oil with a very smooth cloth  slightly dampened with alcohol can give a final shine but that takes serious practice and waxes are easier and safer 

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yes. powder abrasives with soft "backers" ie. cloths, leather or bare hands will contour and not "flatten" the texture  if desired. I'm a big fan of doing the recurve and edge area with my raw fingers so as to be gentle in those areas, they can burn through if not done carefully, using bare hands allows for accuracy of pressure and pinpoint area precision.

 

mmm'mmm' good, Joe's Copal and Amber, rubbed out with pumice and rottenstone,oh my'.

 

post-24788-0-68346200-1473083892_thumb.jpg

 

Thanks so much for the tools Joe, best of the best imo...

 

 

 

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Good info as usual Nate.

 

Jezzupe, The ribs and color are beautiful, but the picture is too dark to see really see the top.  Do you have a picture that highlights the top texture?  

 

Thanks,

Jim

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No matter how you smooth the varnish, cleanup is extremely important. If you are cavalier about cleanup, you will get little zits popping up in the next coat of varnish or French polish. I use Kimwipes with distilled water, and reach into the corners and niches where the dust/detritus will accumulate. I think it was Don Noon who suggested this to me. I also keep a clean apron handy.

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No matter how you smooth the varnish, cleanup is extremely important. If you are cavalier about cleanup, you will get little zits popping up in the next coat of varnish or French polish. I use Kimwipes with distilled water, and reach into the corners and niches where the dust/detritus will accumulate. I think it was Don Noon who suggested this to me. I also keep a clean apron handy.

Thanks Michael, I hadn't considered cleanup, I will now!

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Good info as usual Nate.

 

Jezzupe, The ribs and color are beautiful, but the picture is too dark to see really see the top.  Do you have a picture that highlights the top texture?  

 

Thanks,

Jim

http://www.acousticguitarforum.com/forums/showthread.php?t=440715

 

not lots of texture, being a guitar it's smoother/flatter, but not as flat or smooth as nitro lacquer and a power polisher....boy I tell ya, guy wants to build violins like guitars and guitars like violins, what the bleep man! :lol:

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http://www.acousticguitarforum.com/forums/showthread.php?t=440715

 

not lots of texture, being a guitar it's smoother/flatter, but not as flat or smooth as nitro lacquer and a power polisher....boy I tell ya, guy wants to build violins like guitars and guitars like violins, what the bleep man! :lol:

Thanks, great work!

 

-Jim

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Hi Josh,

 

You can take comfort that you're certainly not the first to consider the merits of whether to sand/polish the final coat of varnish (or after each new coat). A good case can be made for either operation, and it therefore becomes a matter of personal taste. However, my choice— no polishing— is not very popular because many consider the appearance "unfinished," which certainly may be the impression if the greatest care isn't taken in the application of the last coat. Nonetheless, I think the deep, bright gloss can't be duplicated by endless rubbing and buffing with abrasives of increasing fineness, to my eye resembling a perfect-but-soulless automotive finish. Even worse, if it doesn't succeed you're left with a murky gloss because the lower layers reflect light differently than the highly polished final coat.

 

Therefore, if you choose not to rub and polish the final coat you must realize this preference means accepting that a certain number of flaws and defects will invariably show themselves and are permanent, which will, however, evince to future generations that a human hand has actually finished the instrument: after all, don't most of us find it especially interesting when we notice some tiny defect on a great instrument which shows the hand of the maker? 

 

I should also mention in my view that it is essential if the unpolished look is to succeed then the ground must be highly luminous. So, if the old Italian luce di dentro (lit., "light from within") principle has been neglected and a ground has been applied which isn't luminous, then in turn the varnish has no hope of reflecting this luminosity, thus failing to produce the fabled inner fire. I strongly disagree with the idea that piling one transparent layer upon another produces luminosity. A better word (in English) for the effect of a luminous ground and varnish is lambency (a subdued luminescent glow). (I will argue it's only produced when there's some sort of "microscopic pore filler" as Ian Highfield called it; but that's a separate topic from your thread here.)

 

While I still sand/rub/polish, it is only done when really needed, such as to remove a major defect, piece of hair, etc. I also don't exclude various non-abrasive burnishing operations. 

 

I can also give you a neat tip. I quickly concluded when trying to use sandpaper for the first time on a violin that it was almost impossible to hold the paper correctly. So I now cut out small circular or oval (no sharp corners) pieces of sandpaper a little bit larger than my fingertip, and attach them to my finger with a piece of some sort of solid flexible adhesive (e.g., Blu-Tack, UHU), which acts both as a thick-but-flexible backing and a way to secure the piece of sandpaper to my finger. This allows very precise control of the paper/fabric, following every nuance of the surface. On the downside, very small pieces of sandpaper tend to wear out rather quickly, and only a small section can be done at one time (you should also cut out multiple pieces of paper). This also works with fabrics (Micro-Mesh, felt, optical velveteen, etc.). Adhesive-backed sandpaper used in this way is not very effective, since the paper is too thin and you tend to apply more pressure than needed, grabbing the surface and leaving gouges instead of scratches. Sorry, I never got around to taking photos of this method, but it's rather easy to visualize. I'm sure many others are already familiar with this.

 

Speaking of photos, I'll attach some below to illustrate what I call The Perils of Sandpaper, as well as the look of lambency.

 

#1– Shows what happens when you try to polish out sanding scratches with pumice, etc., and oil— you can't do it.

#2 & #3– Illustrate why I dislike sanding: here I was unable to produce a uniformly dull surface; note the large number of "holidays" distinct from the abraded areas.

#4– Vital layers of the varnish can be damaged. Here is my "red pore" layer (I place it above the first yellow-toned ground coat, and below the first varnish coat); in this case the red color in the pores wasn't damaged.

#5– Lambency

 

post-44428-0-56139900-1473356708_thumb.jpgpost-44428-0-32818800-1473356729_thumb.jpgpost-44428-0-07594500-1473356748_thumb.jpgpost-44428-0-30995600-1473356762_thumb.jpgpost-44428-0-40858200-1473356776_thumb.jpg

 

 

Dave 

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Jezzupe, I'm a little behind after traveling for week for work so I finally got around to seeing your video. Really nice sound and playing. I enjoyed it!

Cheers,

Jim

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