Melvin Goldsmith bench

[Melvin Goldsmith]

Varnish drives me crazy & needs to look right under UV light....the latest sample

 

[joerobson]

Varnish drives me crazy & needs to look right under UV light....the latest sample

 

Melvin,

Nice color.  Is this on a ground or white wood?

Jow

[Melvin Goldsmith]

Melvin,

Nice color.  Is this on a ground or white wood?

Jow

Hi Joe,

I just hastily sealed the wood with shellac which is not my actual ground but of course, much faster!

[joerobson]

Hi Joe,

I just hastily sealed the wood with shellac which is not my actual ground but of course, much faster!

 

Melvin,

Easier to see what is going on if one knows the background.  I like color density a lot.

Joe

[DarylG]

Looks great Melvin. Is that color from the varnish alone?

[Melvin Goldsmith]

Looks great Melvin. Is that color from the varnish alone?

Hi Daryl, Thanks, This is just another experiment but I can confirm that all the color is from cooking the resin. I have been looking in the direction of the Brandmair book which tends to find that the primary color is not from pigment. I was also inspired to look in this direction from following the late & great Koen Padding's products and findings and a conversation or two. ( I am not privy to his recipes) I have no idea if my varnish sample is going to work in the long term. I added a bigger pic on the original post. both are scans rather than photo.

[DarylG]

Thanks Melvin. If you don't mind, what is the resin:oil ratio? Also, how many coats of varnish on these samples?

[DarylG]

duplicate 

 

[Melvin Goldsmith]

Thanks Melvin. If you don't mind, what is the resin:oil ratio? Also, how many coats of varnish on these samples?

Hi Daryl the resin oil ratio is 1/1 by weight but I had to add solvent for brushability. 4 coats on the lighter sample and 6 on the darker ( both the same varnish). I also experiment with different ratios with a view to making a lean mix to correspond with the ratio suggested in the Brandmair book with variable results, some of the lean mixes being rather prone to cracking...

[DarylG]

Thanks Melvin. How would you describe it's thickness at this point? It looks thin but it's hard to judge from photos.

[Melvin Goldsmith]

Thanks Melvin. How would you describe it's thickness at this point? It looks thin but it's hard to judge from photos.

Hi Daryl, The paler sample is thin, the darker one is probably going to be about the right thickness once cured. I took a photo on macro of (below) it which seems to make it look thicker than it is.  I quite like the pin holing in the texture which reminds me of the Lady Blunt Strad ( not that I am making any claims for this humble sample which has yet to be cured and tested) I think one factor for the pin holing is the use of solvents which are making this varnish shrink wrap around the texture of the wood. I am experimenting a lot with different solvents in the mix recently i.e  turps, paraffin  lamp oil , white spirit, rosemary oil etc plus some more modern solvents of varying volatility that Kremer offer and finding that these effect the outcome a lot in regard to the look and outcome. What I use on my instruments is generally stuff that I know works reliably...what I am experimenting with here is not yet ready to be used. If I was sane I would buy all my varnish from proper varnish makers like the classic Cremonese probably did but I just can't stop experimenting...It's a compulsion.

[Urban Luthier]

I love the look Melvin. What about thinning to brushing consistency with linseed oil rather than a solvent? I'm slugging through the Brandmair book as well but i confess i simply don't understand how the varnish is cooked to achieve the wonderful colour you are getting!

 

lovely work

 

Chris

[DarylG]

Thanks Melvin. When cooking the resins for color do you find temperature or time to be the critical factor? Cheers,

[Melvin Goldsmith]

I love the look Melvin. What about thinning to brushing consistency with linseed oil rather than a solvent? I'm slugging through the Brandmair book as well but i confess i simply don't understand how the varnish is cooked to achieve the wonderful colour you are getting!

 

lovely work

 

Chris

Hi Chris, You are correct that adding linseed oil will ease brushing but it will also dilute the color of the resins because it remains as a constituent of the varnish. Thanks for your kind words re my varnish sample. I should say that the directions I lately have been looking in are from reading the Brandmair book rather than from recipes within the book but in the footnotes Peter Greiner does give a recipe they tried that was based on their analysis.

[Melvin Goldsmith]

Thanks Melvin. When cooking the resins for color do you find temperature or time to be the critical factor? Cheers,

Hi Daryl,

Both. Most important thing is to keep close observation and make some rules and keep in mind that the next batch of the same species from the same source might not cook the same....

[Conor Russell]

Interesting stuff Melvin.

 

I cooked three batches a couple of weeks ago, a litre of varnish each.

 

The first I made very lean. I found it reached a good string very early, and didn't want to leave it on much longer. It has a strong tendency to crack in a thick coat, and I wonder whether it's cooked long enough.

 

I made two using Krammer dark rosin, and one with a litre of thickened turpentine that I found I had. In the past I have usually started with pale rosin. I think cooking pale resin to dark gives a much brighter, clean varnish, with a much better yellow/red, than starting with the dark stuff. Any Comments?

[Julian Cossmann Cooke]

Hi Daryl, The paler sample is thin, the darker one is probably going to be about the right thickness once cured. I took a photo on macro of (below) it which seems to make it look thicker than it is.  I quite like the pin holing in the texture which reminds me of the Lady Blunt Strad ( not that I am making any claims for this humble sample which has yet to be cured and tested) I think one factor for the pin holing is the use of solvents which are making this varnish shrink wrap around the texture of the wood. I am experimenting a lot with different solvents in the mix recently i.e  turps, paraffin  lamp oil , white spirit, rosemary oil etc plus some more modern solvents of varying volatility that Kremer offer and finding that these effect the outcome a lot in regard to the look and outcome. What I use on my instruments is generally stuff that I know works reliably...what I am experimenting with here is not yet ready to be used. If I was sane I would buy all my varnish from proper varnish makers like the classic Cremonese probably did but I just can't stop experimenting...It's a compulsion.

Melvin, as a fellow varnish experimentation compulsive, I like to think of the affliction as an opportunity for personal growth.

[Melvin Goldsmith]

Interesting stuff Melvin.

 

I cooked three batches a couple of weeks ago, a litre of varnish each.

 

The first I made very lean. I found it reached a good string very early, and didn't want to leave it on much longer. It has a strong tendency to crack in a thick coat, and I wonder whether it's cooked long enough.

 

I made two using Krammer dark rosin, and one with a litre of thickened turpentine that I found I had. In the past I have usually started with pale rosin. I think cooking pale resin to dark gives a much brighter, clean varnish, with a much better yellow/red, than starting with the dark stuff. Any Comments?

Hi Conor,

Thanks for your comment. I can only comment on what you mention as a colleague because I am no expert. 

I think that different resins cook differently, even if I order the same stuff from Kremer for example it seems to cook differently. I guess this is inevitable with natural ingredients until we know more about them.  I think that a lean varnish could be very dependent on having the right resins involved. 

[MANFIO]

Very nice varnish Melvin! I still have some varnish made by Koen but will have to think about what I will use when it is finished...

[Melvin Goldsmith]

A set of linings fitted and glued in a few minutes...It's Sunday and sunny so the list of to do is for Monday.

[Peter K-G]

A set of linings fitted and glued in a few minutes...It's Sunday and sunny so the list of to do is for Monday.

 

That's how I use to do it too, with clothespins, the springs are a little bit too week though, so I have bought some better small clamps now. You have a thin enough mold to get it out? I have to take the mold out before glueing the top linings.

[Melvin Goldsmith]

That's how I use to do it too, with clothespins, the springs are a little bit too week though, so I have bought some better small clamps now. You have a thin enough mold to get it out? I have to take the mold out before glueing the top linings.

Hi Peter. I find that if the linings fit well there's not much pressure needed.  The Old Cremonese glued in both sets of linings before removing the mold. If you use the same type of mold and thickness they did it is no problem to remove the mold with two sets of linings glued in.

[Don Noon]

This has been posted in the past, but again:

you can double the clamping force by cutting off the tips of the clothespins as close as possible to the spring.

[Peter K-G]

Clever!

[Melvin Goldsmith]

Clever!

Yes indeed!...BUT.....If you need a lot of muscle to clamp ribs and linings together you are doing something wrong and also running the risk of distorting your rib outlines...as I said it should be a very simple procedure to bend linings to fit the ribs in a few minutes for the whole structure....If you can't do this easily in a few minutes, you need more practice not stronger clamps.