Jump to content
Maestronet Forums

Science and "Evidence"


Peter K-G
 Share

Recommended Posts

  • Replies 163
  • Created
  • Last Reply

Top Posters In This Topic

23 minutes ago, martin swan said:

Seconded ...

Can someone remind me how to use the "block member" function? 

Let your cursor hover over the member name, then look for the "ignore user" button at the bottom of the pop up screen.

image.thumb.png.f82640c4a05d13650ae9918e88e63a96.png

Link to comment
Share on other sites

12 hours ago, Strad O Various Jr. said:

I am insisting that anyone that has ever used turpine, rosin/oil varnishes knows that they will not dry without UV light,and in Stradivari's time that meant direct sunlight, not just heat.

One questions whether you have any experience varnishing violins at all?

Light and UV are catalysts for drying, they help.  But, drying oils and varnishes should dry eventually anyway.

Likewise, metalic ions, particle content, and even startch can all aide drying. But none are strictly necessary, just helpful.

 

Link to comment
Share on other sites

10 minutes ago, David Beard said:

Light and UV are catalysts for drying, they help.  But, drying oils and varnishes should dry eventually anyway.

If one thinks there is no difference between a six week or less waiting time and a four month or more wait for drying before a bridge can be put on then what you say should be o.k.

Link to comment
Share on other sites

Yeah. I didn't say unaided drying is a good idea, or remotely reasonable in time length.

But if we're talking science and evidence and being accurate with statements, then UV/sun are aides to drying, not essentials to drying.

 

Me, I like using the sun to dry finishes.  It pleases me.

Link to comment
Share on other sites

18 hours ago, David Beard said:

Me, I like using the sun to dry finishes.  It pleases me.

Me Too!

9 hours ago, Wood Butcher said:

I often wondered if the old makers reserved the summer months for varnishing, when the warmer and drier weather would surely be an asset.
 

I would think they did, why would you wait around for months trying to keep the flies and kids out of the sticky stuff.

On the other hand it could give it some time to really wet the wood and make it translucent.

Humm,,,,, do I want it to dry real fast?

I wonder,,,,,,,,,,,,,

Link to comment
Share on other sites

1 hour ago, Evan Smith said:

Me Too!

I would think they did, why would you wait around for months trying to keep the flies and kids out of the sticky stuff.

On the other hand it could give it some time to really wet the wood and make it translucent.

Humm,,,,, do I want it to dry real fast?

I wonder,,,,,,,,,,,,,

Both true, depending on what you use and how, at least in my experience...    Another benefit from not using UV or high intensity UV is that lake pigments tend to fade less.

Link to comment
Share on other sites

11 hours ago, Wood Butcher said:

I often wondered if the old makers reserved the summer months for varnishing, when the warmer and drier weather would surely be an asset.
Rather than today’s system of make an instrument, then varnish it immediately.

I know I don't time by the seasons.  I live where there is lots of sun around the corner for most of the year.  I avoid finishing when the weather is actually bad.  And at times that could mean waiting 6 weeks.  But it would never mean waiting 3 months.   But also, I don't approach finishing as something I expect to take days.  I expect it to take weeks or months in its full footprint.

Link to comment
Share on other sites

10 minutes ago, John Harte said:

Both true, depending on what you use and how, at least in my experience...    Another benefit from not using UV or high intensity UV is that lake pigments tend to fade less.

I once had the weirdest thing happen with alkanet,, it faded to a dull brown in the uv box, only to reappear a few days later as a dark red, much more intense than to begin with. I've only used it once, so what I did I have not a clue.

Making coffee or tea is about as far as my chemistry goes,,,7 years later it still seems stable.

Link to comment
Share on other sites

4 minutes ago, Evan Smith said:

I once had the weirdest thing happen with alkanet,, it faded to a dull brown in the uv box, only to reappear a few days later as a dark red, much more intense than to begin with. I've only used it once, so what I did I have not a clue.

Making coffee or tea is about as far as my chemistry goes,,,7 years later it still seems stable.

This is interesting.  Was the alkanet there as a wood stain or a varnish colourant?

From memory I have only tried alkanet in linseed oil and it faded back to almost nothing, but that was a while ago.  I'm not sure what the actual linseed oil might have been and whether it would have been put in the UV box or exposed to sunlight or left lying around in my workshop..  My best guess is that one of the first two options would have been involved.

Link to comment
Share on other sites

13 minutes ago, John Harte said:

This is interesting.  Was the alkanet there as a wood stain or a varnish colourant?

From memory I have only tried alkanet in linseed oil and it faded back to almost nothing, but that was a while ago.  I'm not sure what the actual linseed oil might have been and whether it would have been put in the UV box or exposed to sunlight or left lying around in my workshop..  My best guess is that one of the first two options would have been involved.

I used acetone to remove the color from the root, added it to the varnish then let it evaporate till the varnish was the right consistency.

A beautiful color,,, But then it then completely disappeared only to leave a dull  light brown, then returned a much more solid, darker, very slightly opaque red.

 

Here's a pic. of even weirder things,

I decided to make this in a day, 16 hrs for the corpus, neck the next day, then in a hurry to varnish, I forgot any drier, so I brushed on some jap drier onto the varnish after it had gotten a bit stiff, the box was pretty warm,,, way too warm for anyone else,, and clear varnish became this red!  Bang!

I'm the kind of guy that makes world class discoveries only because I do things so weird, I stumble abound like a drunk bumping into things, then I hit the right switch inadvertently. But with no notes, who knows what happened. I have varnish samples I would give a lot to know how they were exactly done,, any notes there are,, are a bit shy of complete directions, and sometimes a little bit makes a big difference. Things look different in 30 years,,and  age does wonders to varnish.

IMG_0487.jpg

Link to comment
Share on other sites

11 minutes ago, Evan Smith said:

I used acetone to remove the color from the root, added it to the varnish then let it evaporate till the varnish was the right consistency.

A beautiful color,,, But then it then completely disappeared only to leave a dull  light brown, then returned a much more solid, darker, very slightly opaque red.

Here it is.

 

IMG_4439 rs.jpg

IMG_4437 rs.jpg

IMG_4434 rs.jpg

Link to comment
Share on other sites

59 minutes ago, Evan Smith said:

I used acetone to remove the color from the root, added it to the varnish then let it evaporate till the varnish was the right consistency.

A beautiful color,,, But then it then completely disappeared only to leave a dull  light brown, then returned a much more solid, darker, very slightly opaque red.

Here's a pic. of even weirder things,

I decided to make this in a day, 16 hrs for the corpus, neck the next day, then in a hurry to varnish, I forgot any drier, so I brushed on some jap drier onto the varnish after it had gotten a bit stiff, the box was pretty warm,,, way too warm for anyone else,, and clear varnish became this red!  Bang!

I'm the kind of guy that makes world class discoveries only because I do things so weird, I stumble abound like a drunk bumping into things, then I hit the right switch inadvertently. But with no notes, who knows what happened. I have varnish samples I would give a lot to know how they were exactly done,, any notes there are,, are a bit shy of complete directions, and sometimes a little bit makes a big difference. Things look different in 30 years,,and  age does wonders to varnish.

Evan, thank you for your photos and very interesting replies!

I wonder whether the acetone modified the resin and/or oil in some way that resulted in the slight opacity and more during the drying process(???).  Also Alkanet is pH sensitive and maybe the pH of the resin and/or oil content had some gradual effect(???).  It would be interesting to hear what knowledgeable chemists on this forum might think.

As for your second experience, seems like whatever was in your Japan drier worked in very mysterious ways!  Maybe the heat provided energy enough for something like iron in the drier to react with the resin in some way....

I can certainly relate to what you mention regarding note taking or not.  Too much to try, so little time...

Link to comment
Share on other sites

At  one of the VSA instrument competitions I saw all of the instruments laid out on long white cloth covered tables.  About one third of them had the impression pattern of the cloth fabric weave on their back plates where they touched the table cloth for the week.

My impression (a premeditated pun) was that the varnishes of many of these relatively new instruments were not very hard.

 

Link to comment
Share on other sites

16 minutes ago, Marty Kasprzyk said:

At  one of the VSA instrument competitions I saw all of the instruments laid out on long white cloth covered tables.  About one third of them had the impression pattern of the cloth fabric weave on their back plates where they touched the table cloth for the week.

My impression (a premeditated pun) was that the varnishes of many of these relatively new instruments were not very hard.

 

Mine did that at the 1994 competition.  Had two weeks for varnishing prior to jumping on the plane to get to the U.S...  Even the plush velvet lined case left its mark.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
 Share

  • Recently Browsing   0 members

    No registered users viewing this page.




×
×
  • Create New...