Bending creases

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mikeyb2

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Just as I thought I had got the hang of bending, I bent 2 sets of Brazilian Mahogany the other day, and ended up with slight creasing on one of the sides, the other 3 being ok. I carried on and fitted the blocks and kerfing, thinking the creases might sand out. Now I'm not too sure. So I have 3 options.
Try and sand it, live with it or start again with a set of African Mahogany sides I just happen to have lying around.
I read on other posts that I shouldn't sand it. What are my chances?
thanks Mike.
 
It's usually caused by forcing the bend too early or the heat isn't high enough. The softer the wood the more prone it is to creasing. Sanding might make it a little less obvious although I suspect it's difficult to predict.
 
We would all have had that happen at one time or another. If slight and you have the material thickness, it's quite possible that it will sand out.

However if you're not trying to sell it, this isn't not going to affect the sound at all. Iif it doesn't worry you, then continue on.
 
Allen, the problem is that I am building this for my nephew, who will be contributing to material costs. If it was for me I might live with it. Looks like I'll have to ask him whether he could live with it. I'll try sanding a bit, but like Michael says, it could be unpredictable.
The posts I've read suggested NEVER try to sand them out, but yours and Michaels comments give me some hope. Thanks.
 
Pete Howlett said:
I agree with Allen. Mahogany and korina are very prone to creasing. It is oftern exacerbated when you wet the wood...
Click to expand...

Pete, after you taught me to bend dry when I visited you some time ago, I've had greater success and never use water other than to spritz the wood if there is a chance of scorching. I think I know what I did wrong on this occasion, and that was to stay too long on this one area of the waist and not chase the heat( your expression I think), moving round the bend of the waist. This is why the other 3 sides were ok, after I had realised my mistake on the first side. Thanks again.
 
I've seen a few ukes with creases in them, and honestly most people don't even notice them, even though as a builder they are quite obvious. And one of the owners even said to me that she love the fact that there was a little crease in the waist. Just meant that it was hand built by someone and not churned out in a factory.

It's just all a matter of perspective really.
 
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I find slight stretch marks on a beautiful woman quite sexy. Perfection is overrated.
 
Try doing the dent thing, drop some water on the crease and try to expand the wood. Then sand it out or at least to the point where it is level. I agree that minor flaws are a sign that this is not an exact craft and stuff happens. I know one person that wants absolute perfection in his instruments (and wants it at a low price) and said he did not like one of my guitars as the top had some uneven grain. I think it looks like wood that came from a tree. Ask your nephew what kind of person he is in terms of defects (beauty marks) and build accordingly.
 
"drop some water on the crease and try to expand the wood"

That's good advice.
 
I find this conversation interesting. A crease in the wood in the waist area means the wood has fractured, and all the water in the world in not going to heal it, broken is broken. You can re-enforce the waist from the inside with more wood and glue to make it strong, but the crease is not going away even if you are good enough to hide it with paint or finish. I personally have learned through years to break the wood in two pieces and be done with it. Its your call.
 
Fractured or compressed. The harder the wood the more likely it is to just snap rather than compress. Solid linings that are made from spruce or some other softwood are especially prone to it - linings also tend to be thick. In fact it's pretty difficult not to get some sort of compression marks on thick linings made from a softwood. I wouldn't bin a lining that showed a bit of compression. I've always binned any side that showed it. That's for commercial reasons. If it was an instrument made purely for my own playing then I would use it, providing it wasn't a very obvious fracture.
 
BlackBearUkes said:
I find this conversation interesting. A crease in the wood in the waist area means the wood has fractured, and all the water in the world in not going to heal it, broken is broken. You can re-enforce the waist from the inside with more wood and glue to make it strong, but the crease is not going away even if you are good enough to hide it with paint or finish. I personally have learned through years to break the wood in two pieces and be done with it. Its your call.
Click to expand...

Agreed ..I've tried every trick in the book to hide creases and wrinkles. all to no avail..I've put them on the spindle sander and made them almost invisable but paper thin ..then when FP go's on it stands out even worse.. i've also used filler and paint like a car body repair..but I know it's still a bodge job... It just wastes valuable time trying to fix it, Just like Duane I now just snap e'm in half and start again.
 
From the original description I really don't think the strength of the side will be all that compromised, the question was to make the fault less glaring. In that case the drop of water and the addition of heat might give enough back in order to finish the side without a divot. Will it be still be visible? More than likely but it might be passable once the area is dressed down a little. As said also, it depends on the recipient. I know my nephew would not mind it, I would not give a paying customer a creased side. Also it depends on the wood and the damage. I have repaired sides as I mentioned but I have to say that they were spruce. It doesn't hurt to give it a quick try, if it does not look promising keep the sides for the inside of a laminated project.
 
an update. Thanks everyone, I've tried the above and sanded as far as I want to without thinning the side too much. It's still there but a little less so, and definitely when I wet the wood to simulate a finish. I invited my nephew to come and have a look before proceeding any further. He is happy enough to accept it as it is, probably as it's the lower waist and out of site when playing. Another lesson learnt, I think next time I'll save myself the worry and bin it. Mike.
 
It's a hard thing throwing away a piece you desperartely want to rescue. Be stronger next time and let it go :) For now, you are forgiven it seems...
 
Pete Howlett said:
It's a hard thing throwing away a piece you desperartely want to rescue. Be stronger next time and let it go :) For now, you are forgiven it seems...
Click to expand...

you're absolutely right Pete. The reason we amateurs desperately want to rescue the wood, is mainly in the difficulty of obtaining another piece, and it's cost. Time also, is an issue, having to wait for a new delivery .A back and sides set only comes with one side set as you know. And the UK hasn't the greatest choice of decent suppliers. Of course, professionals like yourself will most likely scrap the piece and just walk into your wood store and grab another.
But, like you say I'll have to be stronger next time. Cheers Mike.
 
but just think of all the poor trees we could save if we did not toss perfectly functional wood because of a superficial flaw. Even if we could only save one tree it will be worth it.




Just kidding.
 
It has a flaw. Still a perfectly valid instrument. It's highly unlikely that it will collapse because of a slight crease at the waist. It will have zero impact on how it sounds or how it plays. As a commercial item it may well be problematic. If it's not a commercial item then it's no big deal at all.
 
You can't sand it out. Even if you have enough thickness to sand it smooth it will show. The wrinkle will show as a dark line with finish.
You could fill it and do a painted finish or a sun-burst with a really dark waist area. It should be structurally OK if it isn't cracked through to the inside
 
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