Rosewood back split at seam

[chimpotle]

Hi all -

Just discovered a new challenge - the rosewood back for my stew mac 000 kit (unbraced) has begun to split at the seam on the lower bout (tail block area. I'm sure this is due to the high humidity that just blew through southern cal in the form of a storm. I had been keeping my top and back in the house, but the conditions had been perfect the past couple of weeks so they went out to the garage, and it turns out i snoozed and "losed". They are both now back in the house.

Photos below but not good quality...

So my question is, what should i do about remedying this split? My first though wax paper on both sides, thin glue in the seam and then place it on a flat spot with a flat weight on top. But i'd like to get some advice before i do anything.

Thanks in advance!

EDIT - its fairly cold here and the heater is running in the house, so i moved the top and back back out to the garage, which is currently 64% RH. Hopefully thats the right decision….

[tippie53]

see what happens in a day or so with the environment change. if you need to fill then your ca will do the trick. It may reswell and you will have to glue it anyway ,hopefully it will close up

[Kevin Sjostrand]

That is what I was going to say, same as John. Let it sit in the higher humidity, when the crack closes in then seep some CA in the crack, a little beyond the end of the crack and just let it sit, no need to clamp as long as it is flat, and you will be better than new.

Kevin

[chimpotle]

Thanks John and Kevin - thats reassuring.

Kevin, i have a follow up question for you, seeing as you are in California as well:

How do you deal with the Santa Ana's? I'm in Camarillo, CA, close to the coast in Ventura County. Usually the humidity is pretty ideal here, but when the Santa Ana's blow through, the RH takes a huge, fast nosedive. And so far this winter we've had to many weeks where its rains for three days and then is followed by the Santa Ana's, resulting in huge swing in RH in a short amount of time.

In December i brought the top out to trace the brace pattern, and when i got started the humidity was in the 50's, but then the winds kicked up and sucked the moisture out of the air and my top in about a half hour.

[Kevin Sjostrand]

Hi Chuck,
I am actually up in the central valley in Visalia. We have low humidity in the summer and higher humidity in the winter, but it does fluctuate from around 25% up to 60%. My shop is half of my garage. It is not heated, cooled or humidified/dehumidified. So far it has not been a huge problem for me. I have some movement in my wood that is stored there, but I have not had an issue with wide swings while I am building that affected the integrity of the build. Two of my guitars went to India to live and I had to try and keep the humidity up while building and in storing the guitars until they arrived in India. It is higher humidity in my house in the summer then in the shop so sometimes I'll bring a project inside while I'm not working on it, but I haven't done that much either.
I wonder if your back was just at a high moisture content when you started, so there was more of a change that stressed it when it dried out. Wood can be finicky this way.
There are some here on the forum with alot more experience then I have, and I know maintaining rel. humidity levels is important, but since I can't, I just haven't worried too much about it, and moved ahead.

Kevin

[chimpotle]

Thanks Kevin. I suppose i'll follow pretty much the same route, with the exception of getting the wood indoors when the wind starts up.

[chimpotle]

Back again...

Unfortunately the humidity just hasnt gotten up enough to swell the crack completely. I kept it in the garage for two days as a storm came through, but it wasnt much of a storm and the humidity would pop up to 60 for an hour, then plummet to 40 or so.

I though the crack had closed, so i wicked in CA. The last inch or so is still open.


So my new questions:

Is the fact that i already wicked some CA going to prevent the wood from swelling now?

If not, i am thinking of getting a humidifier and keeping the back in my studio room for a week - any concerns there?

Finally, any advice on cleaning up the CA that seeped out boht sides at the open parts of the crack? It darkend the RW, and at the edge has a hard candy look to it. Scrape?

Thanks for any and all advice.

[Kevin Sjostrand]

Chuck,
The CA will scrape or sand down the wood and you probably won't be able to find the crack. Some of that last inch is going to be trimmed off I would guess once the top in glued to the rims, and any slight crack still showing you can wick in CA with some rosewood dust and fill it...it will disappear.

Kevin

[Ken Hundley]

My only concern with doing that is, next time the humidity drops, it will split again somewhere else. I think you are better off doing a little sanding, let the dust into the gap, then wick in some CA. It will definitely look dark and stand out, but sand it smooth, and try wiping the whole thing down with naptha...you will see it disappears under any kind of finish....looks like a natural streak in the wood.

[chimpotle]

Thanks for the replies Kevin, Uri and Ken!

Uri - i think you're idea is great, especially in lieu of buying a humidifier, but i think Ken's concern is valid. If low humidity was the the exceptional condition, i think your plan would be the ticket. But my environment is usually low RH, so i'm thinking the wood is kind of in its happy place with the slight gap.

I've played with some scrap from the rosewood headstock overlay, and i think i can work with sweeping some dust into the gap, wicking the CA and then sanding. Fortunately the seam is pretty much dead center and will be supported by the back bracing center strips.

Thanks so much for the help!