Violin Forum/Message Board Forum Index Violin Forum/Message Board
Provided by Violin Vision
 
 FAQFAQ   SearchSearch   MemberlistMemberlist   UsergroupsUsergroups   RegisterRegister 
 ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log inLog in 

Pore filler

 
Post new topic   Reply to topic    Violin Forum/Message Board Forum Index -> Violin Making and Restoration Forum
View previous topic :: View next topic  
Author Message
Joseph Leahy
Member


Joined: 23 Mar 2008
Posts: 98
Location: Ontario, Canada

PostPosted: Mon Oct 14, 2019 12:10 pm    Post subject: Pore filler Reply with quote

Pretty quiet around here. Smile

Just wondering if we can start a thread around the idea of pore filling in the varnish process. Much of the discussion on this topic began with Roger Hargrave's detailed description of his bass build some years ago where he advocated using a slaked lime and water mix as part of the ground. As I remember it, he said that early on he found that doing this added a dimension that he felt was beneficial to the sound and projection of the instrument. There was also an article in the Strad where Greg Alf used pink tripoli as part of his varnish process. Joe Robson does not include this in this varnish process. Since these articles were published, I'm sure a number of us have at least experimented with this.

My interest is in finding out what you do and how you think it affects the look and sound of your varnish.

I have used the both the slaked lime and tripoli. Not sure if I didn't fully wash the plaster of paris but I found it to muddy the clarity of the varnish somewhat. The tripoli seemed to work fine visually. I'm still out on whether either enhances the sound or if this is still largely due to the quality of the arching.

Do you include this step in your varnish process?
Do you think it improves the sound?
Do you think it improves the projection?
Do you think it reduces the clarity of the varnish?
Anything else?

Hope everyone is having a great day and the Canadian's are enjoying a nice Thanksgiving dinner! Beautiful weather here in Ontario.

Looking forward to your comments.

Joe
Back to top
View user's profile Send private message Visit poster's website
L P Reedy
Super Member


Joined: 02 Apr 2009
Posts: 276
Location: Brevard, NC

PostPosted: Mon Oct 14, 2019 6:23 pm    Post subject: Reply with quote

The closest I have come is a little more complicated. I have sometimes applied a thin coat of waterglass, then a coat of 10% calcium chloride to precipitate calcium silicate in the wood, then vinegar to neutralize any remaining NaOH. Any excess acetic acid (vinegar) will evaporate.

Does it help? I'm not sure. At first I thought it did and some of those fiddles were among my best at the time. However, the last time or two that I did it I didn't think I could hear a difference.

With my best application it did not seem to affect the appearance. One or two of the earlier ones showed some white through the varnish at first. I haven't bothered to do it lately.
Back to top
View user's profile Send private message
Chet Bishop
Super Member


Joined: 23 Mar 2007
Posts: 678
Location: Forest Grove, Oregon

PostPosted: Wed Oct 16, 2019 9:51 am    Post subject: pore filler Reply with quote

I mix fine gypsum powder (purchased in garden department of Home Depot) with coffee, and brush it on, then rub it in with my fingers, then rub off excess gunk with a rag.

Why coffee? to wake up the tone, of course! (just kidding...) The coffee imparts a very faint yellowish tan color to the wood, though, as the mixture dries, the gypsum leaves the wood chalk-white. After the wood is completely dry again, I use 400-grit to sand off any excess that I missed with the rag, or, along the purfling channel, I might use a gentle scraper to trim back excess.

However, ALL the gypsum goes "invisible" as soon as I apply the sealer, leaving the coffee stain, and whatever color the sealer is. (I use rosin in turpentine for a sealer...turpentine takes the rosin into the wood, then evaporates, leaving the rosin in the wood.)

Varnish to follow...

Does it work? Who knows? I have gotten good reviews, but there were other "changes" I had implemented about that same time, so I can't say for sure that the gypsum was the key difference. (I had also begun using the hypocycloid arching...also called 'curtate cycloid'...and, yes, I think that makes a difference.)

Mr. Hargraves said that the slaked lime he was using made the biggest single difference in the projection of sound, of any change in his career. That was enough for me to at least attempt to emulate his experience.
_________________
Chet Bishop
https://bluefiddles.com
https://fivestringfiddles.com
Back to top
View user's profile Send private message Visit poster's website
DonLeister
Moderator


Joined: 29 Mar 2007
Posts: 383
Location: Richmond, VA

PostPosted: Sun Oct 20, 2019 9:35 pm    Post subject: Reply with quote

I think our own processes is/can be as important as the materials. Since we all have different processes (even using the same materials) that could lead to a long discussion that I don't think I have the time to engage in for long.
But I'll add my two bits.

If sealing the wood is all we are talking about here try this:
( This is not taking into account any kind of stain that you may have applied )

I apply a varnish, dark and thick like molasses, with a finger and brush. Rub it on well. ( I have usually tanned or lightly stained the wood at this point - tea, oxidation stain, whatever ). I often stain the back different from the top since they take stain differently.
Do a section at a time, not the whole thing.
Rub the varnish off with a clean rag ( t-shirt ) until it won't pick up anymore varnish.

Important- rub it with a stick of soft chalk ( like from Eternity Arts ).
Wipe off the chalk . Any areas that feel sticky, rub with more chalk.
Wipe that off. Keep rubbing any sticky areas with chalk and wiping off.
At this point the wood will not grab the rag and the varnish will feel dry and look burnished.
Set it in the UV box to dry.

This is what I have been doing recently and I like it because it seals so quickly, leaves the instrument dust free. Seems to add very little weight.

Of course your varnish will be different from mine, in color, thickness, drying time, so you will have to use your good judgement while you proceed.
Back to top
View user's profile Send private message Visit poster's website AIM Address
Joseph Leahy
Member


Joined: 23 Mar 2008
Posts: 98
Location: Ontario, Canada

PostPosted: Mon Oct 21, 2019 2:14 pm    Post subject: Reply with quote

Thanks to all for the discussion.

To date, I have applied a number of stains after using a light application of technical gelatin including tea, onion skins, etc. etc. etc. and have used principally the slaked lime applied with water and then two coats of thin varnish. As I said, I found this created a bit of cloudiness in the varnish. Not sure if it's the technical gelatin or the slaked lime but suspecting the slaked lime was not washed well enough or I'm using too big of particles.

I'm getting a very yellow result with tea (orange pekoe) with my current maple so I'm going to run some tests with coffee, as Chet has had success with this. I've also tested JOHA Old Gold water stain which gives a decent base colour.

I like the process Don has outlined and will try that in the future ... but for this one, after some UV, I am thinking of technical gelatin on the top only, then a light stain (either coffee or Old Gold depending on how the wood looks in testing), then varnish diluted 6:1 with mineral spirits which in tests has given good clarity to the base, and then the tripoli/varnish application.

I'm also going to stop in to Home Depot to pick up some Gypsum. I totally agree with you Chet, that the Curtate Cycloid arching is important although I am now using the templates I have created to get close and then use intuition, feel and how it looks to finish the arching.

Thanks again for the discussion.

Joe
Back to top
View user's profile Send private message Visit poster's website
DonLeister
Moderator


Joined: 29 Mar 2007
Posts: 383
Location: Richmond, VA

PostPosted: Mon Oct 21, 2019 8:54 pm    Post subject: Reply with quote

I have a feeling that putting slaked lime (water based ) over gelatin ( water based) could cause the cloudiness. If the slaked lime dissolves into the gelatin , the gelatin will catch it and no oil varnish will be able to make the lime clear again.

I used to put a wet slaked plaster on the raw wood but I found that if it meets any kind of hide glue, the glue can catch the wet plaster and cause light colored splotches.
That might be at the purfling or seams or edges of 'f's.
Back to top
View user's profile Send private message Visit poster's website AIM Address
Joseph Leahy
Member


Joined: 23 Mar 2008
Posts: 98
Location: Ontario, Canada

PostPosted: Mon Oct 21, 2019 9:36 pm    Post subject: Reply with quote

Hi Don, thanks for the comments. That makes sense to me. I’m going to change my process and do some more testing. Thanks again for taking the time to comment.
Joe
Back to top
View user's profile Send private message Visit poster's website
Chet Bishop
Super Member


Joined: 23 Mar 2007
Posts: 678
Location: Forest Grove, Oregon

PostPosted: Sat Apr 24, 2021 2:47 pm    Post subject: Reply with quote

I absolutely agree! If you are using a gelatine sealer, do NOT use the gypsum!

The other sealers make it transparent. The glue-sealer does not, and you can't fix it afterward. (One time error, only!)
_________________
Chet Bishop
https://bluefiddles.com
https://fivestringfiddles.com
Back to top
View user's profile Send private message Visit poster's website
Display posts from previous:   
Post new topic   Reply to topic    Violin Forum/Message Board Forum Index -> Violin Making and Restoration Forum All times are GMT - 4 Hours
Page 1 of 1

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum


Powered by phpBB © 2001, 2005 phpBB Group