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Bow Cleaning Tools/Solvents


Guy_Gallo

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So let's say one was creeping up on bow restoration/re-hairing.

Say one was going to start by learning how to clean and polish old junk bows wihtout doing damage. And then learning how to French Polish them.

What solvents would one need (any links to purveyors appreciated)?

What processes/procedures to follow. I'd prefer to err on the conservative side.

Is straigtening a bow something that can be done over an electric stove, or is a bending (cambering) iron needed.

Any recommended books?

Thanks for any pointers.

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Dear Friend-

I bought a book on eBAy not too long ago from a violin maker named RL Wiles who sells his own (on CD, called "making a violin bow") . He also makes books on "bow re- hair and recamber", and also "violin making and set- up". The link to his "about me" page is: http://members.ebay.com/aboutme/rlviolins.. His self- description is pretty interesting.

rlviolins is his user name. I also bought a bow hairing jig from him. At my request he custom made it so it would be more useful than the stock ones you get from your everyday luthier supply store. It can be adjusted to fit any size bow. His books have pictures that are very helpful, as well as lots of experiential observations like "but don't do ..(whatever, such as drying the hair with a blow dryer)... or you can throw that one out." He seemed happy to offer information as well. Unfortunately I cannot attest to the quality of the jig yet because my brother has hogged it since I had it shipped to him way back in the spring (nor the bow I also bought from him, though I do use it more than any of my others.)

Anyway, this is my suggestion. Take it with a grain of salt because I am beneath the novice level, but it is a start. I thought it was interesting to look at the tools he purchased (located in his "feedback from sellers")LOTS OF DREMEL ones. Again, I am a lowly no- nothing in this respect, but for whatever it's worth...

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Many inexpensive bow sticks have poor grade finishes that don't even hold up to rosin buildup (let alone cleaning), mostly on old brazilwood bows. There are a number of solvents that can be used to clean bows. No one solvent is going to be safe for all finishes, and some are downright poisonous. On many bows with a decent finish I like to use Citra-Solv, not as offensive or poisonous as xylene and a very effective rosin remover, and relatively safe on many finishes. If recambering a bow (and I do use an electric hotplate, it covers a wider area and the heat is easier to regulate), the varnish or French polish (if it has varnish, some are sticks are simply oiled and polished) can bubble during heating. In which case it would need to be removed with alcohol before recambering, then replaced afterwords with a good French polish or Qualasole. I'd practice on a good number of cheap/broken bow sticks before even attempting to work on a decent bow.

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You can use commercial thinner (i.e. toluol) -- (used for the dilution of gloss paints and lacquers etc.) to remove the dirt.

Use spirit alcohol (apply sparingly!) on a towel to polish the bow afterwards. Don't use too much of spirit because it dissolves the varnish. Regards, Anne

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I agree with your excellent advice on bow finishes, Jay.

It's obvious you have "been there, done that".

A few added comments---

The first step, is to study and analyze the camber/bend/twist problems and decide where the force will need to be applied after heating.

Certainly a hot plate would work fine, however, I use an electric heat gun for recambering and straightening... holding and rotating the stick in front of the heat gun laying on the bench. The heat needs to be applied slowly and evenly over a long area and the stick must be heated so hot you can barely hold it. Then sit down and relax... holding, bending, and/or applying a twist to the stick until it cools. Keep a constant pressure on the stick.

"This will take a few minutes" , as my computer often tells me.

If you need to re-do the process, let the stick cool competely before heating again...don't ask me why.

Fixtures, or nails in a board, as recommended by some, are useless -even damaging-experiments in my opinion.

Save your time, and your bows, and do it the old fashioned way.

As Jay said, practice on some junkers! Very important advice!

I too, use Qualasole and it works very well. It is available from

Stewart-MacDonald but not always shown in their catalog.

I hope this makes sense and helps.

Jimbow

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"Qualasole smells really nasty, don't want to think about what it does to your brain ..."

-------------------

You are right, it is potent and there are strong precautions on the label regarding not inhaling, adequate ventilation, etc. which I follow.

For bow polishing, only slight dampening of a double layer of old tee shirt with a few drops is sufficient. This causes a very minimum of fumes. Rapid polishing of the stick with the Qualisol dampened pad quickly results in a nice original looking finish.

It is advisable to do this outside or in the garage to minimize the effect of the fumes. A few minutes is all it takes to polish a stick. Additional coat(s) can be applied after an hour or so, if desired.

As in the use of many varnishes, solvents, gamboge,and other chemicals, one cannot be too careful.

Jimbow

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Well a recipe in a very popular book here states:

Gum lac .........5 1/8 oz

Dragonsblood........1 3/10 oz

Copal............1 3/10 oz

Spirits of wine........21 1/3 oz

Never tried it but who knows... sorry this is bow varnish for brazilwood and pernambucco. Not exactly French polish which is just shellac and ethanol.

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"Qualasole is easier to work than traditional French Polish."

For the purposes of bow restoration, what is traditional French Polish?

------------------------------------

Hi falstaff,

I think it was Jay "Woodland" who made that reference.

I have never done any serious French Polishing of bows although that seems to be the traditional finish.

"The Art of Bowmaking" (an excellent book by the way!) explains that several thin layers of shellac are applied with a cloth with a short drying time in between. After dried,facets are sanded smooth and coated again.Goal on octagonal bows is to produce well defined facets without rounding the corners by using No.600 and progressively finer grades of sandpaper glued to 1" x 6" pieces of 1/4" plywood.

Final polishing is done with MICROMESH cloth, then mineral oil and abrasive powders.

Final finish may be obtained by applying with a cloth, thin coats of shellac with a few drops of mineral oil added then rubbing briskly.

This is a very brief summary of the 2 page description of finishing in the book along with photos of special polishing fixtures to assure flatness of facets.

Reading this fine Limited Edition 140 page book by Joseph Kun and Joseph Regh makes one appreciate the extraordinary amount of talent and detailed worksmanship that is involved in high grade bows by expert bowmakers.

As a comparison, the Robert Alton book, discussed in another thread, covers the complete topic of "Making a Violin Bow' in 6 1/2 pages( 5" X 7") . (Chapter Xll).

The paragraph headed "Polishing" states "The stick may be french-polished or varnished with finest quality oil varnish."

That's it ! The paragraph then goes on to discuss balance and spring in similar generalities.

Jimbow

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Quote: "Final finish may be obtained by applying with a cloth a thin coats of shellac with a few drops of mineral oil added then rubbing briskly."

If you clean the bow good first then use this "somewhat" french polish method you'll get a very good finish on many old bows. I keep small squeeze bottles with different color shellac all dissolved and ready. Then apply with a couple drops of fine mineral oil. You'll be tempted to use more mineral oil but don't. If you have small chips/cracks in the old finish, try to work that area heavily (even with little extra alcohol on your FP pad) to blend the edges of the chip away. I suggest doing everything you can BEFORE making any decision to strip the bow.

Oh, be sure to do ALL(*(&^%$&*) repair work before working your finish.

Best of luck and enjoy,

Regis

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Quote:

As Jay said, practice on some junkers! Very important advice!


There are two large lots of junkers (maybe a few good ones in there, too) selling on ebay right now, eBay item numbers: 3775514504 (37 bows currently @52.00) , and 3775510513 (26 bows currently @26.00) , both w/ about 4 days left.

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