PDA

View Full Version : What is Going on Here? What to do?



sequoia
12-11-2016, 06:28 PM
I'm not a very experienced builder, but I pride myself on making joint seams disappear. I can make them absolutely invisible. Then today I was sanding out a top plate joint and it would not disappear. It was on some new Sitka spruce from a new source and some nice AAA stuff.

What seems to have happened is that the glue (Titebond) seems to have seeped into the wood enough to discolor it along the joint. This is unacceptable to me and basically is some nice spruce ruined. Other than cut the plates apart and start over or use an opaque finish, I am at a loss of what to do. But I'm a bit puzzled why this happened. I've done a bunch of spruce tops and never seen this problem. Second picture is some strong back light.

96259 96260

tobinsuke
12-11-2016, 07:00 PM
Hmmm.... I have limited experience with Sitka, but titebond redcap is my go-to glue. I wonder if others have experienced this (or similar) and since headed it off with a whisper of shellac? I'm curious to read the replies.

spongeuke
12-11-2016, 08:32 PM
Surely it is salvageable in some other project. If not let me know.

Michael N.
12-11-2016, 09:37 PM
Must be something reacting with the glue. Try shooting the outer edge and brushing on some water, then an area with glue, see if there's a colour change.
I've never had that happen with HHG but it may well be that it contains something that reacts to water based glues.

saltytri
12-12-2016, 02:41 AM
I had the same thing happen with Sitka and original Titebond, but only once out of dozens of Sitka tops. Threw the top away. Another top that was glued up in the same way and from the same board was OK. Go figure. I have other sets resawn from the same board with a note on them to try a different glue next time.

Rrgramps
12-12-2016, 04:58 AM
Ouch, cutting it apart, shooting it again, and sparsely re-gluing is the only way to salvage it. Then, hope the glue doesn't seep across the seam again. Redcap tite bond or hide glue if HHG does it again.

Beau Hannam Ukuleles
12-12-2016, 09:09 AM
It isn't the glue reacting to teh wood.
its one (or all of the following trhee things)

1- Bad/gappy glue joint (i doubt it) and this is obvious to look at.
2- Sometimes two dark winter grain lines can merge/be very close and it looks like one dark line.
or
3- Sometimes the wood has discolourisation in that area.

Solution is the same for all 3 things-
1- Cut it in half again,
2- Chop out the discoloured spruce,
3- Re glue

Kevin Waldron
12-12-2016, 10:53 AM
Cut it out!

Don't use TiteBond glue for these kinds of joints........ use HHG, RooGlue Clear, LMI glue, or other........Weep is usually very noticeable in rosette area's.

sequoia
12-12-2016, 04:20 PM
The glue was Titebond original red cap. It was rather an old bottle. What I think may have happened is this: The plates come from their humidity controlled environment at the vendor. Arrive at my house in a downpour. Everything is like a swamp at the moment. I take them out to the shop. Humidity 99%. Shoot the edges exposing all that fresh dry wood to high humidity. Immediately absorbs moisture. Apply glue and the titebond just wicked and followed all that moisture into the wood. That is my current theory anyway since I've never had Titebond weep into surrounding wood like that... Will cut out the area and re-glue. Not really that big a deal just a puzzler.

Michael N.
12-12-2016, 09:47 PM
3 letters:HHG.

Beau Hannam Ukuleles
12-13-2016, 12:29 PM
the titebond just wicked and followed all that moisture into the wood. That is my current theory anyway since I've never had Titebond weep into surrounding wood like that...

I think not.

Titebond doesn't wick like that through cell walls (ie grain lines)- it's just the center of the spruce naturally discoloured a bit.

sequoia
12-13-2016, 05:42 PM
I think not.

Titebond doesn't wick like that through cell walls (ie grain lines)- it's just the center of the spruce naturally discoloured a bit.

OK. So I did some quick experiments today taking different small spruce cutoff pieces from completely different vendors and gluing them together under the same conditions (as in raining)/ Same glue. Result: None of the other spuces showed the discoloration line. So it is the wood and not the glue and not the humidity and not the joint. It is just super spongy stuff that absorbs and discolors between the grain lines. Too bad because the stuff looks great and would have sounded great. Oh well. Not gonna buy that stuff again. A pity. Onward! Into the fog!

Michael Smith
12-13-2016, 07:12 PM
I tend to think Alen's explanation was more likely than not. Can't you just run the tablesaw down the joint and redo.

sequoia
12-13-2016, 08:05 PM
I tend to think Alen's explanation was more likely than not. Can't you just run the tablesaw down the joint and redo.

Sure absolutely I could, but the same thing is going to happen again sure as shootin. Somebody once said that insanity is repeating over and over again the same thing and hoping for a different result. The problem here is the wood. Wood gonna wanna do what wood wanna do. The interesting thing is that this probably is the most perfect, most beautiful piece of spruce I have ever seen. Grain lines: absolutely perfect and parallel. Color: Perfect white cream. The problem is I think this is a piece of wood that looks incredible but that just doesn't function as a piece of wood that is going to make a good soundboard. No real loss. Spruce is cheap. Yeah but it would have looked great. As they say... Next!

Dan Gleibitz
12-13-2016, 08:52 PM
Your buyers must be more picky than me. That wouldn't bother me one bit, as long as the ukulele sounded good.

bluesuke
12-14-2016, 03:57 AM
I think not.

Titebond doesn't wick like that through cell walls (ie grain lines)- it's just the center of the spruce naturally discoloured a bit.

i would agree! Sets out of the same billet the grain will change through out the board