Making a double bass

[Jim Bress]

Harley exudate   

 

[Húslař]

Thanks for all the answers! The French book is very good.
What do you think about Old Wood Italian Golden Ground-may have similar effects like urine?, It does not degrade wood over time? (Have you tried this product Mr. Hargrave?).
Question on Your varnish: You write that most color comes from cooking, so you then add a little dye (what dyes?). Can you write something more about your varnishes and grounds? (can You share with us more recipes?)
Please excuse my curiosity and my bad English-I'm excited young violinmaker who would like to do the job well (not for fame or money).

 

 Thank You!

[Urban Luthier]

i know the thread is long but read through from the beginning -- Roger documents all aspects of the wood preparation, grounding and varnishing along with recipes 

[David Burgess]

Harley exudate   

Goll-dang-it, I just got beat up at a biker bar where I had gone to try to collect some Harley drippings. They called me some bad names too!

 

Confused by this response, I looked in my copy of "Badass Bikers For Dummies", and learned that dripping fluids in a parking lot is a long-standing way of marking territory, sort of like a dog peeing on a fire hydrant. No wonder Harleys leak!

So be very careful when you try to collect Harley exudate. Not sure what I'm going to do now.

 

I might even tell my mom.  

 

And it's Roger's fault.

[Bill Yacey]

Is that the establishment that routinely has 30 or 40 mopeds and scooters lined up outside?  

 

Perhaps this would be worth looking into:

[David Burgess]

Is that the establishment that routinely has 30 or 40 mopeds and scooters lined up outside?

 

Fortunately, I have immunity from getting beat up by moped/scooter riders, because my "significant other" is still a member of the local scooter/moped club, despite no longer having her 50 cc Honda:

http://www.meetup.com/AnnArborScooterClub/members/7947905/

[Bill Yacey]

That's a good thing David! I can imagine it would be rather embarrassing to be thrashed by a guy who rides a pedal assisted 25cc moped!!

 

As a side note, maybe synthetic TCW3 could be used to tone down the red in varnish?

[Urban Luthier]

Ok back to reality for a moment. One more follow up on the horse dung thing -- here is a result of the experiment published on the Mulesaw site. I don't think he saw the results he was looking for, but I expect is results would be better if he exposed the wood to UV light afterwards

 

Chris

[Bill Yacey]

Isn't the whole rabbit urine / horse urine / manure thing  a form of uric / nitric acid treatment? If so, why not forget about the raw sewage and just use a dilute acid?

[Jim Bress]

Isn't the whole rabbit urine / horse urine / manure thing  a form of uric / nitric acid treatment? If so, why not forget about the raw sewage and just use a dilute acid?

Or wash done some beets with a beer or two and pee in a bucket.  You could feed beet roots to your horse (or rabbit) but save the beers for yourself. 

[captainhook]

Isn't the whole rabbit urine / horse urine / manure thing  a form of uric / nitric acid treatment? If so, why not forget about the raw sewage and just use a dilute acid?

No. Birds produce uric acid, which is a VERY weak acid. Mammals produce urea, which is not acidic at all. It converts to ammonia under the right conditions, which is, if anything, mildly basic.

[Bill Yacey]

It must have been the urea I was thinking of. I recall reading something about the collecting of horse urine to make what I thought was an acid, but you're right; it was ammonia.

[DBurns]

Isn't the whole rabbit urine / horse urine / manure thing  a form of uric / nitric acid treatment? If so, why not forget about the raw sewage and just use a dilute acid?

My chemistry prof use to say that just because you have a formula in front of you, does not mean that you know all that is going on.

So nature is so variable that it is rarely in danger of repeating it's themes.

[nagylaj]

The original Amati:

 

http://www.youtube.com/watch?v=lwp8OXSVbm8

 

Roger's copy:

 

http://www.youtube.com/watch?v=Aj67MKgaDaU#

 

Bravo Roger! Master work!

 

If ever the bass will be in Hungary, call me, I would try it!

Edited February 13, 2014 by nagylaj

[Niek]

Dear Roger, this is Niek de Groot the player of the original Amati double bass. A student led me to your weblog. Of course I knew you have been making a copy together with René, but we actually never met, like our instruments!

How very interesting and beautiful to read all the detailed information and see those gorgeous images. I seem to have developed a weak spot for unvarnished instruments....

It also proofs to be a big inspiration for all kind of professionals. Thank you so much!

 

I do have two remarks/questions about your descriptions of the original from 1680.

 

-As Peter Biddulph also describes in his certificate, back and sides are made of (Italian) ash. Similar to what I heard about those Amati cellos. One colleague of yours once explained me this was because it was easier and probably cheaper to find this kind of wood in bigger parts.

Now you describe it as being chestnut. As I know some kinds of ash look rather similar to chestnut, but what do you think?

 

-Another thing is the scroll; the peg-box and of course the neck are renewed over the years. Now I don’t see the peg-box as particularly being ugly or a mess, but indeed we miss the Amati-hand there. Most Italian basses from the earlier years have a new or strongly altered peg-box. Since roughly between 1850-1920 they where changed (due to internationalization of the musical world, ha-ha) from their original 3-string build to a 4- or even 5-string set-up. It is really similar to the fact that as you know most early string-instruments also have ‘new’ necks due to the increased angle we play with now. It is hard to find an original on the market, although I recently met a beautiful Lupot violin with its original neck.

We often see that the actual scroll was replaced at the same time, but that is not the case here. As Biddulph also states the scroll is original and recognizable. Please have mercy that all my predecessors over 334 years have, by taking such good care of the bass, used soft covers or worse, which somehow rubbed away the sharp edges.

 

Anyhow, thanks a lot again and I’m sure you will receive similar Oh’s and Ah’s wherever you go with the copy, as I get with the original.

It would be great to hear and see them together once. As a matter of fact I’ll will record it’s first ever solo-CD next week with sonata’s by Brahms, Hindemith and Gubaidulina. That would save us a least half of the transportation, which is indeed a one act-opera, but usually very enjoyable. I knock some wood now….

 

All best,

 

         Niek de Groot

 

 

[Roger Hargrave]

Dear Roger, this is Niek de Groot the player of the original Amati double bass. A student led me to your weblog. Of course I knew you have been making a copy together with René, but we actually never met, like our instruments!

How very interesting and beautiful to read all the detailed information and see those gorgeous images. I seem to have developed a weak spot for unvarnished instruments....

It also proofs to be a big inspiration for all kind of professionals. Thank you so much!

I do have two remarks/questions about your descriptions of the original from 1680.

-As Peter Biddulph also describes in his certificate, back and sides are made of (Italian) ash. Similar to what I heard about those Amati cellos. One colleague of yours once explained me this was because it was easier and probably cheaper to find this kind of wood in bigger parts.

Now you describe it as being chestnut. As I know some kinds of ash look rather similar to chestnut, but what do you think?

-Another thing is the scroll; the peg-box and of course the neck are renewed over the years. Now I don’t see the peg-box as particularly being ugly or a mess, but indeed we miss the Amati-hand there. Most Italian basses from the earlier years have a new or strongly altered peg-box. Since roughly between 1850-1920 they where changed (due to internationalization of the musical world, ha-ha) from their original 3-string build to a 4- or even 5-string set-up. It is really similar to the fact that as you know most early string-instruments also have ‘new’ necks due to the increased angle we play with now. It is hard to find an original on the market, although I recently met a beautiful Lupot violin with its original neck.

We often see that the actual scroll was replaced at the same time, but that is not the case here. As Biddulph also states the scroll is original and recognizable. Please have mercy that all my predecessors over 334 years have, by taking such good care of the bass, used soft covers or worse, which somehow rubbed away the sharp edges.

Anyhow, thanks a lot again and I’m sure you will receive similar Oh’s and Ah’s wherever you go with the copy, as I get with the original.

It would be great to hear and see them together once. As a matter of fact I’ll will record it’s first ever solo-CD next week with sonata’s by Brahms, Hindemith and Gubaidulina. That would save us a least half of the transportation, which is indeed a one act-opera, but usually very enjoyable. I knock some wood now….

 

All best,

 

         Niek de Groot

 

Not much of a question then Niek? Let me begin by thanking you so very much for the chance to copy this bass. I am 66 years old and although it was a lot of work, it was the best fun I have had in years. Now about the wood! Let me begin with a story about G B Guadagnini. The whites of Guadagnini's purfling have long splits in them. This is a known characteristic of this maker. For decades these whites were said to be acacia wood. This was repeated in several publications until in the late 1970's a small sliver was microscopically analyzed at Kew Gardens in London. Here it was found to be white (the sap wood) walnut. I wrote about this in the 1980's. The point being that everyone knew what was meant when the word acacia was being used. We all knew what it looked like. However, it is very often the case that we know what something looks like, but don't know exactly what it is. The obvious other example is poplar and willow woods. Both these woods occur in all colors, from dark brown, through red and grey, to white. However, without the leaves, these woods can only be identified microscopically.

 

Now before writing this certificate Peter asked me about the wood on this bass. I told him that I had seen two Hieronymus II cellos with identical wood. More importantly they had the same kind of patina. I have since seen photographs of a third Hieronymus II cello. 

 

As to whether this wood is Ash or Chestnut; the time I saw the first cello I was told by a cleaver expert that the back and ribs were Chestnut. This kind of stuck in my brain. I am sure that, like Guad’s purfling, this wood has never been analyzed. But I have a large lump of ash in my cellar that looks very similar. So, if you were to put thumb screws on me I would probably squeal, “Ash!”   

 

Now for the head! For reasons that I described and you have also underlined, old bass pegboxes have often been replaced. There is no doubt that this was the case here. However, until I began to design the head from a plaster cast of a Bros Amati cello head, (the explanation as to why this is possible with Amati instruments is on the blog), like everyone else I had thought that the head was a later work. It was only when I began to examine the lines and flow of the turns that I realized that it was almost certainly the original scroll. No-one else could have produced these turns so well. They matched my plaster cast exactly. And yet the surface had been altered quite heavily. These two factors just did not match. The only explanation is that the head was seriously altered as the pegbox was being grafted. Add to this the fact that the scroll wood was extremely soft and you can see why everyone rejected this head.

 

So you can buy me a glass of wine for finding this out and also for coupling the cellos with the bass. My comments about these details made Petter and several others take a second look. I sometimes wonder why I don't write certificates myself. (Not really)

 

By the way, I think, like the so-called five stringed Amati cellos, these early basses were almost certainly fitted with three strings. This is because the quality of the early gut strings meant that the bass string was simply too thick to swing. (Rather like me in fact)

 

Now that is what I call an explanation (get that from a dealer) and it comes largely as a result of doing a copy. It is astounding what comes out of the woodwork when you make a copy.  

 

Good luck with the recording. 

[Roger Hargrave]

PS I am working with a member of MN on an edited version of this blog with photos. It will go onto my web site, I hope some time soon. 

[Urban Luthier]

Ich auch!

[nagylaj]

Hello Roger!

So I write here. About the varnish:

Do You cook colophon and mastic alone without linseed oil? And put into the oil at the end? And how long do You cook it? You

write that, you put nitric acid in it, to fast oxidation. But not much,

cos its toxic. But how much do Yo use approximately? I use now old wood 1700 varnish, but

in the future i would like to cook my own. What do You think, does nitric

acid work with old wood varnish, to make it darker?

[Roger Hargrave]

 

Hello Roger!

So I write here. About the varnish:

Do You cook colophon and mastic alone without linseed oil? And put into the oil at the end? And how long do You cook it? You

write that, you put nitric acid in it, to fast oxidation. But not much,

cos its toxic. But how much do Yo use approximately? I use now old wood 1700 varnish, but

in the future i would like to cook my own. What do You think, does nitric

acid work with old wood varnish, to make it darker?

 

 

I don't recall writing that I add Nitric Acid. Perhaps someone else did that on this blog. It is an old trick. We made Nitric varnishes when I was at the violin school in the 1970's. Nitric certainly causes the varnish to redden, but is very dangerous stuff. It is the basis of many explosives. You can make Nitro Colophony which I am told is pretty explosive and quite unstable. However, I have always been more worried that it will destroy the structure, as well as oxidizing the varnish, (I don't really know). However, if you do want to know more about Nitric varnishes consult the Fry book. It is available again.

As for the colophony, (or whichever resin you choose), cook it long and slow. Don't be tempted to switch it off, because it will very likely burn when you start to heat it again. Don't be tempted to turn up the heat either. Be prepared for a heavy electric bill. I cannot tell you how long to cook it for. One very cold winter I needed varnish badly and I cooked outside for several weeks. (No joke!) Normally it only takes a few days. Cook it WITHOUT the linseed oil. When it is finished you add the cooked resin to the hot linseed a bit at a time and cook for about one hour until it is blended. Linseed and several resins can become exothermic. If you don't know what this means with regard to linseed oil, I suggest you find out before you start. 

Thank you for asking again here. This way everyone benifits. 

[LinkMan]

 

I don't recall writing that I add Nitric Acid. Perhaps someone else did that on this blog. It is an old trick. We made Nitric varnishes when I was at the violin school in the 1970's. Nitric certainly causes the varnish to redden, but is very dangerous stuff. It is the basis of many explosives. You can make Nitro Colophony which I am told is pretty explosive and quite unstable. However, I have always been more worried that it will destroy the structure, as well as oxidizing the varnish, (I don't really know). However, if you do want to know more about Nitric varnishes consult the Fry book. It is available again.

 

As for the colophony, (or whichever resin you choose), cook it long and slow. Don't be tempted to switch it off, because it will very likely burn when you start to heat it again. Don't be tempted to turn up the heat either. Be prepared for a heavy electric bill. I cannot tell you how long to cook it for. One very cold winter I needed varnish badly and I cooked outside for several weeks. (No joke!) Normally it only takes a few days. Cook it WITHOUT the linseed oil. When it is finished you add the cooked resin to the hot linseed a bit at a time and cook for about one hour until it is blended. Linseed and several resins can become exothermic. If you don't know what this means with regard to linseed oil, I suggest you find out before you start. 

 

Thank you for asking again here. This way everyone benifits. 

 

The varnishes of the Italian violin-makers of the sixteenth, seventeenth and eighteenth centuries, and their influence on tone

by George Fry ...

[Carl Stross]

 

 

 

As for the colophony, (or whichever resin you choose), cook it long and slow. 

 

 

Roger, what temperature more or less ? ( sorry if you've already mentioned that )

[Urban Luthier]

 

Hello Roger!

So I write here. About the varnish:

Do You cook colophon and mastic alone without linseed oil? And put into the oil at the end? And how long do You cook it? You

write that, you put nitric acid in it, to fast oxidation. But not much,

cos its toxic. But how much do Yo use approximately? I use now old wood 1700 varnish, but

in the future i would like to cook my own. What do You think, does nitric

acid work with old wood varnish, to make it darker?

 

 

In addition to what was noted above, Roger wrote this somewhere in the blog. Don't ask me exactly where i don't know.

 

on oxidization and nitric acid

 

"Nitric Acid has a long history amongst violin makers. Several books and treaties have been written about Nitric acid varnishes. I have experimented with Nitric recipes several times. In conclusion, I can say that I have never been happy with the idea of either wood, or varnish ingredients, being treated with nitric acid. Nitric Acid is extremely aggressive and at some point these treated substances will come into contact with the musician’s skin. Until quite recently nitric acid has been used to stain boxwood chinrest, tailpieces and pegs. I have often wondered if, at least in part, these might have been the cause of those unsightly marks on the necks of so many violinists. In fact since the 1980s, unless they were specifically requested, I have not used boxwood fittings on my instruments."

 

and this

 

"... regrading oxidization... There are many ways of approaching this. For many years nitric acid has been employed, in spite of the fact that it was not available to the classical Cremonese makers. Creating violin varnishes with the help of nitric acid has taken many forms. It has also been used in various ways to colour the wood before the varnish was applied. Amongst the most famous formulas are those described by Fry in his 1904 book “Italian Violin Varnishes”. In the dim and distant passed I have had some success with this book. However, I would add one massive caveat; nitric acid is extremely dangerous and can create explosive substances with a great many organic materials. This includes nitro/colophony."

 

On preparing colophony and notes on safety

 

"Although there are several alternatives, I mostly use colophony as my main resin and this is the basis of the varnish that I will be using for the bass. Colophony has a similar refractive index to Venetian and Strasburg turpentine’s, but it is probably the easiest usable resin to find and to work with

 

A stainless steel asparagus pan is perfect for cooking resins it is about 18 inches high and 6 inches in diameter. Having decided how much varnish I wish to make, I cook the resin low and slow. After quickly loosing various volatiles, it will gradually reduce in volume considerably. I cook outdoors, well away from anything inflammable. I have a small temporary shelter to keep the cooker out of the rain. We get a lot of rain. The shelter is well ventilated and allows me access to stir the resins.

 

Especially in the early stages this cooking process will give off a lot of highly inflammable gases. If you decide to attempt this you will need to be very aware of the possibility of fire or even an explosion. Clothing especially wools and cottons can absorb fumes and become highly flammable. You should always have a fire extinguisher capable of putting out an oil-based fire. You also need to be aware of the possibility of an exothermic reaction. Never cook on an open flame. There are several historical reports of people being killed while cooking varnishes. In most towns and cities cooking varnish was only allowed outside the city walls. I know personally several people that have received severe burns. Best of all is gaining access to a lab, where extractors and proper temperature controls are possible.  If you do not have access to a laboratory extractor this needs to be done in the great outdoors. Apart from the danger there is the smell to consider. Cooking colophony in towns and cities is likely to cause problems with neighbours and authorities.

 

Apart from the risk of fire and an exothermic reaction, if you allow the colophony to get too hot it will burn and turn an ugly black/brown/green colour.

 

Initially, to save time, I cooked large quantities of varnish. This turned out to be a mistake. Without the appropriate equipment large quantities are difficult to regulate. The main problem is keeping an even temperature throughout. It is very easy to burn the bottom of the batch, while the top is being cooled by the surrounding air. Because even a small amount of burning will spoil the entire batch, it is best to cook smaller amounts. Once cool the resulting red resins can be mixed together with oil at a later stage. Any burned batches can be discarded. As I pointed out earlier, whatever the resin a considerable amount will evaporate. Because the amount is often quite drastically reduced, instead of simply adding this red resin to the oil, I add it to oil that has already been blended with some colophony in the simple way that I described earlier. I cannot tell you exactly how much; because this will depend upon how much of the red resin has boiled away. In the final analysis I just try to keep to the ratios that I mentioned earlier.

 

I have never found this job easy and especially at the beginning I burned quite a few batches. Moreover, I have shown many people how I make my varnishes, but in the end they all eventually find their own way. If you live in a desert or close to the Arctic Circle your requirements will be very different. I have cooked in frosty conditions and in summer temperatures of 30+ c. In cold conditions my electric bill was always huge."

 

As for the blending of the resin and linseed oil together... 

"Linseed oil heated to 200C. Powdered resin and mastic tears slowly added and stirred for 1 hour. The still warm varnish was filtered"

 

Hope this helps

 

 

 

 

[Urban Luthier]

Roger, what temperature more or less ? ( sorry if you've already mentioned that )

I don't believe an actual temperature for cooking the resin was quoted in the thread. Discussion around the topic lead me to make a note of "a cooking temperature between 120-130 degrees C until the desired colour was reached". I can't remember the exact source however, it may be the Brandmair strad varnish book. I'll check later today and get back

 

[Carl Stross]

I don't believe an actual temperature for cooking the resin was quoted in the thread. Discussion around the topic lead me to make a note of "a cooking temperature between 120-130 degrees C until the desired colour was reached". I can't remember the exact source however, it may be the Brandmair strad varnish book. I'll check later today and get back

 

Thank you - that would be nice to know.