Making a double bass

[baroquecello]

As far as I know, urine partly turns into ammonia when it gets older. Ammonia reacts in some way with wood, making it darker and grey, if I am not mistaking. This is probably what you have seen on your wood, I would guess.

[La Folia]

There must be nicer ways to get ammonia.

[Oded Kishony]

Another ancient method was the dry distillation of red deer horn. Referred to as sal amonniac or spirits of hartshorn .

 

Oded

[Alfieri]

Another ancient method was the dry distillation of red deer horn. Referred to as sal amonniac or spirits of hartshorn .

 

Oded

.

 

http://www.etsy.com/listing/58622150/spirit-of-hartshorn-smelling-salts

[fiddlecollector]

The chief comonent in urine is urea,not quite ammonia but a nitrogen compound none the less. It has many interesting properties. Such as it can denature proteins,it can extend the working pot life of hide glue in low concentration  ,a browning agent in mass produced Pretzels,although many independent bakers use sodium carbonate or caustic soda(at least i think so). Whether any of these are good for violins is debatable.

[Peter White]

Thank you all for this information.  I have read the recent book Stradivari Varnish and the 2007 VSA papers on Stradivari's varnish.  These two scientific works of great importance do not agree on the number of coats or layers Stadivari used.  The most recent research argues strongly that there are four steps basically in Strad's varnish technique: sealing, staining (darkening), clear coat, and color coat.  I tend to believe with the authors of Stradivari Varnish that the wood was somehow darkened in order to achive varnishing with two coats of gum resin and linseed oil. This would account for quality tone and wear of the colored varnish over time. However, we do not know how Stradivari darkened the wood. Mr. Hargrave uses rabbit urine and UV light. I have made linseed oil varnish for 35 years and find it very difficult to get color from the varnish alone no matter how long or how hot it is cooked.  So how do you all think Stradivari darkened his wood in rainey, cloudy Cremona and simultaeously produced 1300 instruments, more or less? How would he have had the time and to use multiple layers of linseed oil varnish? Do you all really think that one color coat would turn an instrument a dark, vibrant red? In my opinion the so-called 'secret" to Strad's varnish is that there was very little varnish on dark wood. In other words, the secret is that there is very little varnish!!!

Help me out on this, please.

[joerobson]

Thank you all for this information.  I have read the recent book Stradivari Varnish and the 2007 VSA papers on Stradivari's varnish.  These two scientific works of great importance do not agree on the number of coats or layers Stadivari used.  The most recent research argues strongly that there are four steps basically in Strad's varnish technique: sealing, staining (darkening), clear coat, and color coat.  I tend to believe with the authors of Stradivari Varnish that the wood was somehow darkened in order to achive varnishing with two coats of gum resin and linseed oil. This would account for quality tone and wear of the colored varnish over time. However, we do not know how Stradivari darkened the wood. Mr. Hargrave uses rabbit urine and UV light. I have made linseed oil varnish for 35 years and find it very difficult to get color from the varnish alone no matter how long or how hot it is cooked.  So how do you all think Stradivari darkened his wood in rainey, cloudy Cremona and simultaeously produced 1300 instruments, more or less? How would he have had the time and to use multiple layers of linseed oil varnish? Do you all really think that one color coat would turn an instrument a dark, vibrant red? In my opinion the so-called 'secret" to Strad's varnish is that there was very little varnish on dark wood. In other words, the secret is that there is very little varnish!!!

Help me out on this, please.

 

Peter,

Welcome to the forum.  These are all good and interesting questions which I am sure will have a broad range of answers.  In order to preserve Rodger's thread on the bass project, I suggest you re-post this response as a separate topic. That way we do not muddy the water for Rodger.

I look forward to this new discussion.

Joe

[Michael_Molnar]

I think new members cannot start a new topic. Nevertheless, there is another one we started on varnish.

 

Peter, put this in "Cooked down resin colors in varnish."

[Jeffrey Holmes]

http://www.maestronet.com/forum/index.php?/topic/328546-darkening-the-violin-wood/

[Roger Hargrave]

Sorry, Im on the road at the moment. Well not quite, that was a bit of old hippy talk. I just snatched a few minutes to see what's going on. But it will be some time before I get to finishing the bass. See you later. R

[Roger Hargrave]

The viola was delivered yesterday. Here are a couple of quick snaps. Sorry about the quality. I try to use natural light, but I had to do this under the big garden umbrella. I am off to England (Oxford) for the Strad exhibition tomorrow and the varnish hut is still not complete because of the rain that we have been having, so it will be a while before the base is looking anything like this. Asuming that it ever will look anything like this.

[La Folia]

...it will be a while before the base is looking anything like this.

Will the bass ever look like that?

[Roger Hargrave]

Will the bass ever look like that?

 

In the words of a man born in the north of England (me), "I bloody well hope so!" But I'm not sure that it will be spelt like that.

[Christopher Jacoby]

Beautiful.

[Roger Hargrave]

Just to keep you all informed. It has been raining and lightening and thundering for weeks. The golf courses are all closed, so this is the reason why I have not finished the shed that I really do need in order to continue with the base. But today I managed to do some more to it between showers so it is almost ready. I just need one good dry day. So sorry, but I have not forgotten.  

[Roger Hargrave]

Ladies and Gentlemen at last a sunny day. I kid you not. This has been the worst summer in my ?? years on this earth.  But now as you can see the shed is finished. It has been painted and waterproofed and is almost ready for action. Tomorrow my son in law is coming with my daughter to wire up the lights and then I can begin the varnishing process. Those that have not switched off will have gone on holiday so I will probably be writing this for myself. But…

 

The bass has also been in action on this first sunny day. As I have already pointed out it has been treated with Koen’s primer I&II mixed 50/50 together. Normally once everything was completely dry, the bass would have been be placed in UV light until it became nice and brown. As you can see it has already gained some color just waiting for me to get the new light box finished. I had it outside in the sun most of this afternoon, but I had to set up my office alongside. Claudia and I are big bird fans and we do a lot to attract them, but it has caused some minor irritations. Some years ago I had hung a freshly varnished violin on the washing line. The birds had a competition to see who could dump the most guano on the head and ribs. So today I spent the afternoon being a scarecrow for the bass. Not particularly difficult in my case.     

 

As well as the birds the varnisher’s best friends were out in force; I mean flies. I tried to get a picture of two making love on the back, but I had to make do with one leaving some fly guano on the head. 

 

This last picture is not a parrot, it's a woodpecker taken yesterday. They love tapping on resonating surfaces she would have had a great time with the bass. 

[robertdo]

No doubt such a large instrument is an invitation for birds...

I see you leave the bass and the chair having a private conversation under the sun while you're hiding under the shadow of the tree.

[Roger Hargrave]

Yes, I might live in Germany, but my skin is northern English light blue. I might complain about the rain, but I respect the sun UV rays. 

[Urban Luthier]

Bass aside, your garden looks lovely Roger

 

looking forward to the varnishing process (of the Bass, not your garden)

 

Chris

[LinkMan]

[LinkMan]

Ladies and Gentlemen at last a sunny day. I kid you not. This has been the worst summer in my ?? years on this earth.  But now as you can see the shed is finished. It has been painted and waterproofed and is almost ready for action. Tomorrow my son in law is coming with my daughter to wire up the lights and then I can begin the varnishing process. 

 

 

BudBox XLarge 2m Grow Tent

[Roger Hargrave]

You’re a bit late with the helpful advice, but it looks useful and appears easy to collapse when the 'feds' do a raid to check out who is producing and dealing basses. I am sure that the ‘feds’ will be monitoring all sales of these boxes and I don't want to get caught with a bass in my attic. Even a half finished one can get you ten years. Don’t believe all of those Machold fraud stories. He was actually caught smuggling a bass into Austria.  Dealing in basses is forever on your record. I understand that some countries don't allow immigration for anyone caught trying to deal or import basses. 

[Berl Mendenhall]

Roger, I made your Plaster of Paris ground.  I used a plastic paint stirrer with my electric drill and it worked very well.  It only took a day and a half to make.  I changed the water several times, and it turned out almost like talcum power.  I've used pumice and water for years but this stuff looks better, much finer.  I put it on a fiddle with water and it worked in the pours much easier than pumice.  I won't get a chance to put any varnish on it till later this week though.  With pumice and water you have to be really careful not to tear the soft spruce up.  If you rub to hard it's like sandpaper on wet wood.  Thanks

[Michael_Molnar]

Hmm. Reminds me of the time-travel phone booth from Dr. Who.

 

Go back in time to Cremona, swap the instrument with one of Strad's, and return. What a pleasant surprise to see how much your instrument improved in Roger's "tanning booth".

 

[Trevor Davis]

I am a huge fan of your work.  It was quite a surprise to find that you were building a bass.  I had to post these pics of the bass I am currently making using the technique of baroque violin construction you described in your article "The Method of Construction Used by the Cremonese Makers circa 1550-1750" in VSA v.10 No.1.  The bass is a Gagliano so there is probably no real reason to use a Cremonese method other than my personal intrigue and probably misguided belief that there appears to have been a center mould.  I would love to figure out how basses were constructed according to different schools, but until then I am just trying tons of different traditional techniques and seeing if I can make them work.  Suggestions, comments?  I'll try anything!