Official Luthiers Forum!
http://luthiersforum.com/forum/

CA wicking through Shellac?
http://luthiersforum.com/forum/viewtopic.php?f=10101&t=52066
Page 1 of 2

Author:  jfmckenna [ Wed Jun 19, 2019 10:39 am ]
Post subject:  CA wicking through Shellac?

I don't get it. And I really didn't notice this till I put the first coat of finish on after finish sanding. Like the wicking took place under the top layer of wood or something. I was hoping the amber shellac would hide it and to some extent it did but dmnit if this isn't disappointing. The guitar on the left has the exact same rosette installed in the same manor. This is torrified red spruce too which interestingly is very hydrophobic.

Anyone have this problem before?

Image

Author:  bcombs510 [ Wed Jun 19, 2019 11:14 am ]
Post subject:  Re: CA wicking through Shellac?

Sorry that happened. Just a heads up I can’t see the pic.


Sent from my iPhone using Tapatalk Pro

Author:  jfmckenna [ Wed Jun 19, 2019 11:17 am ]
Post subject:  Re: CA wicking through Shellac?

I updated the pic.

Author:  SteveSmith [ Wed Jun 19, 2019 11:21 am ]
Post subject:  Re: CA wicking through Shellac?

Well, I still can't see the photo after the update and a refresh on my part. I use two coats of 1# shellac just in case I don't get everything with the first coat. Don't know but perhaps the torrefied top is different? I'll be interested to find out what's going on because I'm just starting my next guitar and it will be my first with a torrefied red spruce top.

Author:  jfmckenna [ Wed Jun 19, 2019 11:38 am ]
Post subject:  Re: CA wicking through Shellac?

God I hate freakin' Google Photos.

How bout now?

Image

Author:  Colin North [ Wed Jun 19, 2019 11:51 am ]
Post subject:  Re: CA wicking through Shellac?

I take it you are talking abut CA used for the rosette rings, and shellac was used to seal the channels.
How many coats of what cut shellac did you use?
I normally used 3 coats 1lb shellac or 2 coats if I'm using 2lb cut.

Author:  Barry Daniels [ Wed Jun 19, 2019 11:58 am ]
Post subject:  Re: CA wicking through Shellac?

That is a complete bummer. Is there any other fix other than a retop?

What brand of CA?

Author:  TimAllen [ Wed Jun 19, 2019 12:18 pm ]
Post subject:  Re: CA wicking through Shellac?

Beautiful guitars! I'm really sorry this happened.

The 2nd time I used CA for rosettes I had a similar problem, albeit less prominent. I thought it was probably caused by not applying enough shellac. Since then I put on 3 coats of shellac, about a 2 lb cut, and haven't had staining.

Author:  jfmckenna [ Wed Jun 19, 2019 1:06 pm ]
Post subject:  Re: CA wicking through Shellac?

I only used one coat of shellac. Obviously thats a problem but then that's all I have ever done too.

Author:  SteveSmith [ Wed Jun 19, 2019 2:04 pm ]
Post subject:  Re: CA wicking through Shellac?

Can see the photos now - that really sucks to have something like that show up on such a nice guitar. Guess I'll start using 3 coats of 1# cut.

Author:  jfmckenna [ Wed Jun 19, 2019 2:19 pm ]
Post subject:  Re: CA wicking through Shellac?

Yeah it's danm depressing is what it is. I guess I'll have to have 'that talk.' I'd rather build another guitar then retop it. It actually looks far worse on camera and the pick guard will cover the lower half of it. I did some Googling around and found an old comment by John Arnold who said it happened to him and eventually it faded away. I can only hope.

[headinwall] [headinwall] [headinwall] [headinwall] [headinwall]

Author:  wbergman [ Wed Jun 19, 2019 2:25 pm ]
Post subject:  Re: CA wicking through Shellac?

Haven't read every post, so maybe this was addresses.

Have you sanded it back to see if the effect is reduced?

Author:  mountain whimsy [ Wed Jun 19, 2019 2:48 pm ]
Post subject:  Re: CA wicking through Shellac?

What a bummer! I'm scared to death every time use CA for rosettes or bindings. I've done it, but use three coats of shellac before diving in. This might make me revise that thinking, given that there are good alternatives to CA.

Author:  jfmckenna [ Wed Jun 19, 2019 3:07 pm ]
Post subject:  Re: CA wicking through Shellac?

wbergman wrote:
Haven't read every post, so maybe this was addresses.

Have you sanded it back to see if the effect is reduced?

That's the odd thing about it. It's almost like it wicked in right under the surface of the top of the wood. As I sanded it, more of it became exposed so I stopped. Since I was using an dark amber shellac I thought it would blend, it did but not quite enough.

Author:  J De Rocher [ Wed Jun 19, 2019 5:05 pm ]
Post subject:  Re: CA wicking through Shellac?

That's really a drag. Are those rings made up of short segments of abalone? Is that why you use CA for this type of rosette? I'm asking about the method because I haven't made this kind of rosette, yet.

Author:  Clay S. [ Wed Jun 19, 2019 5:42 pm ]
Post subject:  Re: CA wicking through Shellac?

I wouldn't retop it. I would do a burst. Mask off the abalone rosette and purfling carefully and add enough color to hide the stain and then go darker at the edges. When I had some CA wick in and stain the top I wound up doing a burst to hide it.

Author:  banjopicks [ Wed Jun 19, 2019 8:22 pm ]
Post subject:  Re: CA wicking through Shellac?

Are we talking about those lines that go end to end? I'm guessing not but I'm not sure.

Author:  jfmckenna [ Thu Jun 20, 2019 7:27 am ]
Post subject:  Re: CA wicking through Shellac?

banjopicks wrote:
Are we talking about those lines that go end to end? I'm guessing not but I'm not sure.

No that's just in the wood, those lines are. In my mind though I can't help but think that has something to do with it. The wood is torrified, it's cooked, and it's almost like this particular piece is susceptible to wicking. IDK how to say it.

What I am taking about is if you look at the rosette like a clock and 12 o'clock is at the center seam toward the tail block as pictured you can see staining at 2,4,8, and 10 o'clock. Pretty much just adjacent to the long natural lines which is why I got to thinking.

In fact the other guitar was the same top, it had the same line markings on it but since it's a small guitar I placed them outside the profile.

Author:  doncaparker [ Thu Jun 20, 2019 7:53 am ]
Post subject:  Re: CA wicking through Shellac?

I’ll just say what I think, and hope it doesn’t come off as harsh. Please know that I don’t intend it as a criticism; it’s just what I see when I look at this guitar.

I think worrying about that little amount of staining on a top that looks like this is the same as the Elephant Man worrying about a pimple. The eye of the casual viewer is not drawn to the rosette stains; it is drawn to the huge streaks that make this top look like reclaimed decking. I think you should embrace the staining as part of the torrified wood look, which is already very prominent on this top.

So, I wouldn’t do anything drastic on this guitar to fix the staining. I would probably develop a well-deserved aversion to using CA anywhere near spruce in the future, but I already have that.

Author:  johnparchem [ Thu Jun 20, 2019 7:54 am ]
Post subject:  Re: CA wicking through Shellac?

jfmckenna wrote:
banjopicks wrote:
Are we talking about those lines that go end to end? I'm guessing not but I'm not sure.

No that's just in the wood, those lines are. In my mind though I can't help but think that has something to do with it. The wood is torrified, it's cooked, and it's almost like this particular piece is susceptible to wicking. IDK how to say it.

What I am taking about is if you look at the rosette like a clock and 12 o'clock is at the center seam toward the tail block as pictured you can see staining at 2,4,8, and 10 o'clock. Pretty much just adjacent to the long natural lines which is why I got to thinking.

In fact the other guitar was the same top, it had the same line markings on it but since it's a small guitar I placed them outside the profile.


My thought was the dark lines almost mask the staining in the areas on the rosette. In the picture anyway they look close to the same color and could read as echos of the natural staining. I get that in real life they can look different than one view in a picture. You are correct they will not sand out. With one coat of shellac, I suspect there were areas in the channels that were not sealed. So the depth of the stain is probably equal to the depth of the channel. Thin CA can wick a long way when it hits endgrain, I have had CA applied around the brass inserts on a bolt on neck wick up to the top of the heel. I think back to the celery in dye experiment many of us did in school, to what is happening.

Author:  jfmckenna [ Thu Jun 20, 2019 8:08 am ]
Post subject:  Re: CA wicking through Shellac?

doncaparker wrote:
I’ll just say what I think, and hope it doesn’t come off as harsh. Please know that I don’t intend it as a criticism; it’s just what I see when I look at this guitar.

I think worrying about that little amount of staining on a top that looks like this is the same as the Elephant Man worrying about a pimple. The eye of the casual viewer is not drawn to the rosette stains; it is drawn to the huge streaks that make this top look like reclaimed decking. I think you should embrace the staining as part of the torrified wood look, which is already very prominent on this top.

So, I wouldn’t do anything drastic on this guitar to fix the staining. I would probably develop a well-deserved aversion to using CA anywhere near spruce in the future, but I already have that.


Do you think those lines come out as a result of the cooking process? That's kind of what I was wondering. Like it's an internal 'highway' for sap and when it got cooked it all exited there or something. IDK just thinking out loud.

Author:  Mike Franks [ Thu Jun 20, 2019 8:29 am ]
Post subject:  Re: CA wicking through Shellac?

I have struggled with the "ring around the rosy" a few times, in spite of using a shellac sealer. Here is what I found to be an effective preventative:

1. Flood the rosette channel with thinned fish glue using an appropriate artist brush. Be generous and fill the channels. Wipe some thinned fish glue on the top surface around the perimeters of the channels. Let it penetrate well into the end grain.
2. After a minute or 2, blow out the glue with an air hose or dry it with paper towels.
3. After the hide glue is dry (I put the top in front of a fan for 30 minutes or so) you will have an effective barrier that won't be attacked or thinned by the solvent effect of thin CA.

Regarding John's problem of the CA wicking through the neck heel when gluing the threaded brass tenon inserts, I prevent this by first spraying a generous amount of accelerator on the neck heel and letting it penetrate before gluing the inserts. Any thin CA that tries to wick through to the heel gets cured before is all the way through the heel.

Mike Franks
http://www.mjfranksguitars.com

Author:  banjopicks [ Thu Jun 20, 2019 8:42 am ]
Post subject:  Re: CA wicking through Shellac?

I have to ask, why is using CA so important in the first place, if it causes this much trouble?

Author:  Ken Nagy [ Thu Jun 20, 2019 8:44 am ]
Post subject:  Re: CA wicking through Shellac?

I don't see anything. They both look cool. I would have thought that CA would act more like a HHG ghost, and prevent the stain or shellac or varnish from coloring the wood. Are you saying that it makes the wood darker? A couple tiny areas around the rosette? Looks like the rest of the wood. The wood looks amazing. I used Red Spruce once on a violin, but I threw it away. The wood looked really nice, but the belly kept splitting with the grain. Over and over again. Bad luck I guess, but I haven't gone back to it.

John, so you are saying that before using CA on in a channel, or maybe anywhere else, the area has to be sealed first? Maybe especially on very dry, or torrefied wood?

Ok a couple of new posts.

Fish glue doesn't create ghosts? I don't know. I know even regular wood glue will. I don't know of any way to get away from them besides gluing first, trying to wipe up with hot water, and then crape or sand down.

Author:  johnparchem [ Thu Jun 20, 2019 8:55 am ]
Post subject:  Re: CA wicking through Shellac?

Ken Nagy wrote:
I don't see anything. They both look cool. I would have thought that CA would act more like a HHG ghost, and prevent the stain or shellac or varnish from coloring the wood. Are you saying that it makes the wood darker? A couple tiny areas around the rosette? Looks like the rest of the wood. The wood looks amazing. I used Red Spruce once on a violin, but I threw it away. The wood looked really nice, but the belly kept splitting with the grain. Over and over again. Bad luck I guess, but I haven't gone back to it.

John, so you are saying that before using CA on in a channel, or maybe anywhere else, the area has to be sealed first? Maybe especially on very dry, or torrefied wood?

Ok a couple of new posts.

Fish glue doesn't create ghosts? I don't know. I know even regular wood glue will. I don't know of any way to get away from them besides gluing first, trying to wipe up with hot water, and then crape or sand down.


CA can wick into end grain and run along the grain for awhile. It is a stain and not a ghosting effect. On some top wood the stain can be a florescent green. So yes, do not use thin CA in an unsealed channel.

In this case it looks like the natural stain of the wood. I personally like tops with long dark streaks. The tops that drive me crazy are the perfectly clean and even tops that show everything.

Page 1 of 2 All times are UTC - 5 hours
Powered by phpBB® Forum Software © phpBB Group
http://www.phpbb.com/