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Bent my first side. Questions. (large photo alert)
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Author:  Gtrman13 [ Fri Dec 11, 2009 12:43 am ]
Post subject:  Bent my first side. Questions. (large photo alert)
I started a thread on light bulb benders recently. Thank you to everyone who replied. You're advice and collective experience is invaluable to someone such as me. Anyway, it seemed the general consensus from the previous thread was that I should buy a heating blanket. I looked into doing this, but I simply don't have the cash flow at the moment. I may decide to do it in the future, but I figured I'd just use what I already have and it can be a good learning experience at the least.

Well, after doing all of my research and prep work and getting my nerves up, I bent my first side tonight. What a nerve racking experience! It was pretty scary, but after I bent the first bout I knew everything would work out. I just didn't want to split it into pieces! Anyway, everything seemed to work just fine except that I may have some scorching in a few places. There seemed to be some grayness in a few places and a few little black spots. The picture below is of the worst of the spots. I'm guessing I didn't have enough moisture in these areas, but maybe one of you will tell me different. I'll be bending the other side tomorrow, so I just want to get some information to make sure I don't make the same mistake(s). Thanks for your help.

Image
Author:  JohnAbercrombie [ Fri Dec 11, 2009 1:07 am ]
Post subject:  Re: Bent my first side. Questions. (large photo alert)
I re-sized your pic- hope you don't mind.
There are many 'resizer' sites online- http://www.resize2mail.com/ seemed to work for your pic.
Some folks are on dial-up or pay for their bandwith, so best to keep the file sizes down if possible.

That doesn't look very 'burnt'- a bit hard to tell in a pic, without 'before and after'.
You will have to sand the sides a bit after the body is assembled, so that may clean up the look a bit.

How long did it take to bend?

What is the side clamped to, in the picture?

Cheers
John
Author:  Daniel Minard [ Fri Dec 11, 2009 3:36 am ]
Post subject:  Re: Bent my first side. Questions. (large photo alert)
That doesn't look like scorching to me. If you are using a fox bender with bulbs, the side wouldn't get that much heat on the outer surface. To get scorching on the outside, the inside would be burned to a crisp.
I have gotten stains similar to that with my spring steel slats leeching rust into the wood. Iron stain on wood is often black, just like that. (Iron splinters from steel wool will make a horrible mess on unfinished wood, if the wood gets damp.)
I now make sure the aluminum foil is in good shape before I start bending. I don't trust paper alone as a barrier between a non-stainless slat & the side.
I may be off in left field on this, but to me, it doesn't look like a "too much heat / not enough moisture" problem.
The paler shadows should sand out... The really dark spots may be there forever, to remind you of just one more inch on the long learning curve.
Good luck & don't be discouraged! It really IS a long curve... And I promise there will be more trip-ups along the way.
Author:  woody b [ Fri Dec 11, 2009 6:06 am ]
Post subject:  Re: Bent my first side. Questions. (large photo alert)
I use spring steel (not stainless) slats because they work best for me. What I do is wrap my slats in foil. The foil will last for several bends. I use paper on both sides of the wood per Todd's bending tutorial.
Author:  Fred Tellier [ Fri Dec 11, 2009 11:28 am ]
Post subject:  Re: Bent my first side. Questions. (large photo alert)
It looks to me like some of the sap in the wood came to the surface and scorched, this will scrape and sand out if that is what it is. Use of foil as suggested above if wrapped around the side will help hold the moisture in the wood longer and might help.

Fred
Author:  Bailey [ Fri Dec 11, 2009 11:48 am ]
Post subject:  Re: Bent my first side. Questions. (large photo alert)
I agree with Fred.....I think you have a cell sap blowout because of heat. Your issue looks small and will probably not be an issue.
Many times you will have small pockets of sap held with in a few wood cells and heat will expand those cells and rupture. If no heat is applied these cells lay dormant and end up crystallizing with age. Even crystallized pockets will re solidify with heat and rupture through a grain cell to the surface. You can also run into these crystallized cell areas when you reach them in the sanding or scraping phase. I find soft and hard pockets in carving projects all the time because I usually work with wood much thicker than luthier material. No way to know where these buggers are.

If your lucky, the sap pockets are still buried within the wood and just escaped through a open grain cell. A light scraping or sanding might take care of the visual discoloration, however, beware...the deeper you go the bigger the pocket may become. I have had to clean out a pocket in carvings and fill or plug with a matched grain piece of wood to save the project.

Kent
Author:  mateo4x4 [ Fri Dec 11, 2009 12:19 pm ]
Post subject:  Re: Bent my first side. Questions. (large photo alert)
I have similar issues on occasion. More often than not, it will sand out without an issue.

-Matthew
Author:  Gtrman13 [ Fri Dec 11, 2009 2:57 pm ]
Post subject:  Re: Bent my first side. Questions. (large photo alert)
Thanks for the replies, folks. Well I'm glad to hear it isn't scorched. Hopefully the flaws will sand out, but if they don't it's not a big deal. That side will be the one facing downward, so it won't be as visible.

So I took everyone's advice this morning when I bent the second side and I added paper and aluminum foil to the sandwich. Would ya believe it, the side came out perfect!

And to answer one of your previous questions about what the side was clamped to in the picture, I built a mold with a lip on the outside for the freshly bent side to be clamped to while it cools and dries. I don't know if it was really necessary or not, but I saw someone else using something similar and figured I'd give it a shot.
Author:  Fred Tellier [ Fri Dec 11, 2009 3:21 pm ]
Post subject:  Re: Bent my first side. Questions. (large photo alert)
Quote:
I built a mold with a lip on the outside for the freshly bent side to be clamped to while it cools and dries. I don't know if it was really necessary or not, but I saw someone else using something similar and figured I'd give it a shot.


Just leave the side in the bender until it reaches room temperature.

Fred
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