www.KitGuitarsForum.com

Learn to Kit Build a Guitar. Learn to Scratch Build a Guitar. Learn EVERYTHING Guitars Here!
It is currently Sun Dec 08, 2019 10:33 am

All times are UTC - 5 hours [ DST ]




Post new topic Reply to topic  [ 8 posts ] 
Author Message
PostPosted: Mon Nov 25, 2019 12:07 pm 
Offline

Joined: Sat Mar 24, 2018 5:41 pm
Posts: 32
Location: Durham, NC
I am in the beginning stages of two builds: one a dred cutaway and the other a 000. Both are going to have torrified tops but I am beginning to get concerned with how the torrified wood is reacting to tape removal.

I use the tape joining method, and on one torrified top (the 000) I had very little "pull-up" of the fibers after using some heat to soften the glue. However, on the second top, which I have not joined yet, I had considerable pull-up when I taped the halves together to joint the edge prior to joining.

This caused me to do a bit of internet searching, where I found a number of people talking about problems with tear-out of grain when doing binding, even when they applied heat.

I didn't find anything that talked about an "aha" moment regarding this issue, and no mention was made of doing a wash coat with shellac, which I have found on other non-torrified wood helps with pull-up considerably.

Does anyone have any ideas or experience dealing with this? Your help would be greatly appreciated.

Thanks,

_________________
------------

Rex


Top
 Profile  
 
PostPosted: Mon Nov 25, 2019 12:27 pm 
Offline

Joined: Sun Mar 09, 2014 8:13 pm
Posts: 2044
Tearout can be a problem with any tape, especially on Adi spruce. I prefer to put a wash coat of 1/2 to 1 pound cut of shellac on all of my tops, not only to help with the tearout, but to keep the spruce clean when I bind with bright colors like padauk or redheart.

It helps with the tape as well. But, I've found that if you pull off the tape slowly, tearing it away close to the top (not straight up) and you pull perpendicular (at a right angle) to the grain, you will virtually eliminate tearout.

I have a photo of this. I'll find it and post it.


Top
 Profile  
 
PostPosted: Mon Nov 25, 2019 1:42 pm 
Offline

Joined: Fri Mar 03, 2006 7:09 pm
Posts: 5986
Location: Hegins, Pa
I am starting to seal them with shellac before I do anything they tend to pull up wood fibers pretty easy

_________________
John Hall
Blues Creek Guitars Inc
Authorized CF Martin Repair Center
president of Association of Stringed Instrument Artisans
http://www.bluescreekguitars.com


Top
 Profile  
 
PostPosted: Mon Nov 25, 2019 3:01 pm 
Offline

Joined: Sat Mar 24, 2018 5:41 pm
Posts: 32
Location: Durham, NC
Thanks for the replies.

Diane, you mention putting on the wash coat before doing anything, would that mean you would do it even before routing for the rosette? And John, do you do a coat of shellac even before sanding and joining the two halves?

I planned to seal the rosette routed areas with a wash coat before putting in the rosette but hadn't thought about a wash coat even earlier.

_________________
------------

Rex


Top
 Profile  
 
PostPosted: Mon Nov 25, 2019 3:22 pm 
Offline

Joined: Sun Aug 24, 2014 12:27 pm
Posts: 19
I use a wash coat before cutting the rosette channel. Much cleaner results.

Brent


Top
 Profile  
 
PostPosted: Mon Nov 25, 2019 7:30 pm 
Offline

Joined: Sun Mar 09, 2014 8:13 pm
Posts: 2044
I do my wash coat after joining and cutting out the top shape, but before doing any routing. If you do a wash coat before joining, you would have to do it before shooting, or using a joiner in prep to joining. If you do a wash coat after prepping the wood for the center seam, but before gluing, you run the risk of getting shellac on the surface(s) to be glued. The seam will be weak, because the glue needs pristine wood surfaces for a strong bond.

I use 3M green 233+ tape to join the center seam of tops. I do it without any shellac prep. I remove the tape by peeling it to one side or the other. I pull low, and to the side, keeping it at a 90° angle to the grain. I've not had any problems with tearout along the seam. I just built 3 guitars, 2 adi and one torrified adi, with no problem. I also just joined a bearclaw sitka the same way, with no tear out from the tape.

After joining the top, and cleaning it, I cut the top out, then wash coat with shellac. I do this before installing the rosette to eliminate tearout from installing the rosette.

So my sequence is:

1. Join the sides, with tape or jig, with pristine wood (no shellac)
2. Cut out top
3. Wash coat of shellac (1/2 to 1# cut)
4. Install rosette
5. Cut soundhole

Here is a sketch of how I remove the tape from the center seam. I hope the sketch helps and doesn't further confuse you. I've not had any tearout when I remove the tape against the grain. I do it slowly, keeping the tape close to the top of the guitar. It's a peeling rather than pulling motion.

For the life of me, I can't find the photo, but if you need a photo, it's absolutely problem at all. I'll take one for clarity. Just ask.

Attachment:
Notes_191125_182840_56d_1.jpg


You do not have the required permissions to view the files attached to this post.


Top
 Profile  
 
PostPosted: Mon Nov 25, 2019 9:12 pm 
Offline

Joined: Sat Mar 24, 2018 5:41 pm
Posts: 32
Location: Durham, NC
Diane,

Thanks so much for your very detailed instruction. I appreciate your trying to find the photo, but the drawing you did is very clear.

I have already joined both tops using the tape method. Both tops were torrefied, but one was definitely more finicky. A friend who knows a lot more than me tells me the problem top had quite a bit of runout.

_________________
------------

Rex


Top
 Profile  
 
PostPosted: Tue Nov 26, 2019 8:42 am 
Offline

Joined: Fri Mar 03, 2006 7:09 pm
Posts: 5986
Location: Hegins, Pa
the only thing to add to Diane's post it to watch the grain fibers and if they are running to the neck on one side they head for the tail on the other so pull in line with the grain fibers. I like the rolling off of the tape like D does.
it is all about grain direction.

_________________
John Hall
Blues Creek Guitars Inc
Authorized CF Martin Repair Center
president of Association of Stringed Instrument Artisans
http://www.bluescreekguitars.com


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 8 posts ] 

All times are UTC - 5 hours [ DST ]


Who is online

Users browsing this forum: No registered users and 4 guests


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 post attachments in this forum

Jump to:  
Powered by phpBB® Forum Software © phpBB Group