Let's talk about Ground

[joerobson]

Hello all,

In the previous pop thread someone noted that I might be a proponent of pop or related substances as a ground.

As a varnish maker and someone who conducts varnishing workshops I am a proponent of knowing the tools and processes to control the desired effects on your instrument.  Information is key.  Lack of information gets you lost...and being lost and varnishing is no fun.

In my personal work varnishing instruments, one of the things I do not use is a grain filler of any sort.

There are many ways and many reasons to use the laundry list of ground methods.

Let's talk.

on we go.

Joe

 

[Mark Norfleet]

Marvelous!  I look forward to seeing where this goes.    

 

[uncle duke]

Are grain filler and ground the same thing?

[sospiri]

Why do recent research papers focus on entirely different preconceptions?

Echard et al and the oil ground. And the other researchers promoting the contemporary Cremona ground?

Something is very wrong somewhere.

[joerobson]

17 minutes ago, uncle duke said:

Are grain filler and ground the same thing?

Grain filling us one method of applying (various) solid material to the surface.  It acts primarily as sealer.

[Don Noon]

I suspect that this thread could go on forever, as the choices for ground (and varnish) are infinite, and every maker seems to find their own favorite.

Generally, I see that ground that seals too well (thick, and/or minimal penetration) kills off contrast in maple flames (bad), but also kills off blotchiness on spruce (good).  At the other end of the scale, penetrating ground can burn maple flames (bad) and do even worse on spruce.  It needs to be tested and balanced, even for each different piece of maple, as they can vary a lot in how much they absorb.

Acoustically, oil-containing coatings tend to have higher damping, so I try to minimize the amount necessary by using resin/solvent on the wood first... or some protein layer.

For the aesthetic and acoustic reasons mentioned, I use slightly different materials and methods for the ground on spruce vs. maple.

[David Burgess]

1 hour ago, joerobson said:

As a varnish maker and someone who conducts varnishing workshops I am a proponent of knowing the tools and processes to control the desired effects on your instrument.  Information is key.  Lack of information gets you lost...and being lost and varnishing is no fun.
 

Lots of us are varnish makers. Is this an advertisement for your varnish workshops?

[sospiri]

7 minutes ago, David Burgess said:

Lots of us are varnish makers. Is this an advertisement for your varnish workshops?

Well I don't buy from Joe, but he still gives me free advice, so there's that.

[joerobson]

18 minutes ago, David Burgess said:

Lots of us are varnish makers. Is this an advertisement for your varnish workshops?

C'mon David....if this were an advertisement Jeffrey Holmes would kick my skinny old man butt.

[sospiri]

38 minutes ago, Don Noon said:

Acoustically, oil-containing coatings tend to have higher damping, so I try to minimize the amount necessary by using resin/solvent on the wood first... or some protein layer.

Therein lies the mystery of what many perceive as the Cremonese sound. The damping.

It's definitely a big issue. I don't know why the contemporary Cremona school won't accept it? 

Edgar Russ seems to have an enquiring mind though. 

If you look at the original thread from November 2009, there was so much I learned studying the information presented. Things I have tried to discus, but the impetus has been lost here.

There seems to be a generally fear that certain ideas can be career suicide. I hope we can get past this. There are good reasons for and against, but correct technique requires careful application. It's too easy to apply too much oil ground, but it's also quite easy not to.

[joerobson]

If using, presumably linseed, oil viscosity control is important.

[Peter K-G]

The summer has arrived and varnish is on my mind 

But this thread is Joe's and it's about ground, so Joe why do you use varnish as a ground?

[joerobson]

1 minute ago, Peter K-G said:

The summer has arrived and varnish is on my mind 

But this thread is Joe's and it's about ground, so Joe why do you use varnish as a ground?

The ground I use is a 5 step process the final application being  ground varnish made from raw resin and linseedoil in a 4 resin to 1 oil proportion.  It is tough and does not create a significant film thickness.

[Peter K-G]

Yes, you have said this before

I hope you understand that because it's you starting this kind of topic, you also get direct questions you might not want to answer

 

[Peter K-G]

So gently my question again, why do you put different kind of varnish mixtures as a ground (Varnish = resin,linseed,turp in different proportions)

[joerobson]

2 minutes ago, Peter K-G said:

Yes, you have said this before

I hope you understand that because it's you starting this kind of topic, you also get direct questions you might not want to answer

 

I am open to almost all questions. 

[joerobson]

24 minutes ago, Peter K-G said:

So gently my question again, why do you put different kind of varnish mixtures as a ground (Varnish = resin,linseed,turp in different proportions)

This formula satisfied my needs as a tool.I wanted a surface which was resistant to wear and the variety of issues created by human use.  Also the tendency of other formulas were toward film thickness  ie build up.

The initial 4 applications are not varnishes...just resin.

 

[Urban Luthier]

Any thoughts on the research shown in the wonderful Guadagnini book by S&Z? Analysis suggests the use of a pore filler.

[MANFIO]

In the past I used my Marcina oil varnish in  a paste with pumice that I rubbed in the wood. It worked well. But I am not using this anymore.

 

[Bodacious Cowboy]

1 minute ago, MANFIO said:

In the past I used my Marcina oil varnish in  a paste with pumice that I rubbed in the wood. It worked well. But I am not using this anymore.

 

OK. I'll ask the obvious.

if it worked well, why don't you use it anymore?

[MANFIO]

2 minutes ago, Bodacious Cowboy said:

OK. I'll ask the obvious.

if it worked well, why don't you use it anymore?

I just changed to something I find better.

[Bodacious Cowboy]

1 minute ago, MANFIO said:

I just changed to something I find better.

better in what way?

[MANFIO]

Just now, Bodacious Cowboy said:

better in what way?

Easier to apply. It takes a lot of time rubbing the paste and removing the excess...  but I can try it again in the future. The type of pumice used makes a huge difference too.

 

[Peter K-G]

1 hour ago, joerobson said:

This formula satisfied my needs as a tool.I wanted a surface which was resistant to wear and the variety of issues created by human use.  Also the tendency of other formulas were toward film thickness  ie build up.

The initial 4 applications are not varnishes...just resin.

 

Resin and turp?, cooked?, how? 

Have to ask

 

[Jim Bress]

3 minutes ago, MANFIO said:

Easier to apply. It takes a lot of time rubbing the paste and removing the excess...  but I can try it again in the future. The type of pumice used makes a huge difference too.

 

When testing different pore fillers mixed with varnish after reading the Greg Alf article, I found no visual difference between different pumice grades, pink tripoli, or the fine gypsum (selenite) from Kremer. However, the fine gypsum was much easier to apply. Probably due to less friction associated with particle size.