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Hi all,

Planning on bending two sets of reclaimed mahogany today, one cuban, one honduran. I wetted then thoroughly last night in super soft two, wrapped them in tin foil and left them overnight. Question is, do I dry them off, or bend them still wet, or dry them and wet them again with water?

I'm a beginner and my plan is to heat to 110, clamp the waist partly down, bend lower bout at 110, Upper at 120, finish waist at 130, cook for five Minutes, cool for an hour, cook for another five minutes at 130, cool for an hour and then remove my perfectly bend side with no scorching, crackling, rippling or anything else undesirable.anyone see any problems?

Thanks,
Mike

Your talking degrees Celsius, right?

Yes.

I had some difficult to bend Honduran mahogany. John Hall gave me this advice and it works, you should be finished up by the time it hits 100c.
When mine hit about 150f I have the rear bent, immediately bend the front, then the waist. slightly damp. Can't say about supersoft. Good Luck, O & OO

No need to dry the sides. Yes, still use water (although you shouldn't need much).

_________________
Josh House

Canadian Luthier Supply
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Per the SS2 recommendation, I let the sides dry - weighted between paper towel overnight.
I believe this avoids staining during heat bending and ensures the SS2 has time to work its magic.
I believe 150f is a little cool to be starting the bends - especially with mahogany.
Have a peek at John's Hall's excellent youtube tutorials.
He starts the bends at 250f which I have found to work well.
I do partial waist (1/4" gap) first, then lower bout, upper bout, then finish the waist.
By that time the temp is 300f and I flip from full power to variable to cook for 10 mins or so at 300f - done!
If using spring steel it is critical to wrap the slats in foil to avoid blackening of the sides.
Also, in the sandwich I use a layer of lightly spritzed brown paper on each side of sides for the moisture component rather than spray the wood directly.

I use it on figured woods and hog - not needed for EIR....

+1 on all the above.

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The name catgut is confusing. There are two explanations for the mix up.

Catgut is an abbreviation of the word cattle gut. Gut strings are made from sheep or goat intestines, in the past even from horse, mule or donkey intestines.

Otherwise it could be from the word kitgut or kitstring. Kit meant fiddle, not kitten.

Just to report back, bent the first honduran side still wet from super soft, bent very well, quite a lot of staining but it Sands out. Second side I rinsed the super soft off in the shower, towelled it down and left it to mostly dry.also bent very well but with less staining. I'll report back on my flat sawn cuban sides...

I'm sure everyone else already knows this, but just in case you don't.....use aluminum foil to wrap sides. I thought I'd be clever and thrifty and use a roll of brown masking paper. What a mess. Paper 'melted' and bonded with wood (had to sand it off in spots!) and still got staining of wood. (more sanding) Live and learn.

Aluminum foil can be helpful while bending but not-so-much-so if bending Koa or Black Acacia which are well known to turn a bit green.... if in direct contact with metal (this includes bending slats) during the bending process. Instead a craft paper wrap for these woods and you will be good to go without the dreaded green discoloration.

SS2 is a veneer softener and is used for purposes other than what we do. It will work at the cellular level. In bending I played with a number of ways to use this as we also use heat.
I found that just using the SS2 and a allowing about 1 hr of dry time worked well in bending the wood. Maple for what ever reason needs very little water with this and will keep bending is allowed to so clamp that into a mold as soon as it cools.

I use heats in F of
lower bout 220 to 250F Upper 250 to 275F and waist at 275 + F and then allow the heat to rise to 325 to 375. Mahogany and maple like a bit more heat. Once this heat is reached you back it off as wood will scorch in about 5 min at this temp but you need this sometimes to set the bend.
Allow a few about 15 min around 220 F to cook out any moisture and allow to cool ( about 30 min) then clamp into the mold and to the next side.

_________________
John Hall
blues creek guitars
Authorized CF Martin Repair
Co President of ASIA
You Don't know what you don't know until you know it

Well, you can lead a horse to water......

Not meaning to be an "old woman", but you were told that SS II is
1) inflammable, and
2) not particularly good for you
and also given a link to MSDS sheet, which I did ask you to read.

Just to point out
1) Bending a SSII wet side involved heating it to above SSII's flash point temperature in a non-explosion proof fixture
2) Will have produced unnecessarily large quantities of vapour in the area of said fixture (and presumably someone requiring to breath was close by the bender)

By all means, feel free to ignore this post, but I felt obliged to point this out.

_________________
The name catgut is confusing. There are two explanations for the mix up.

Catgut is an abbreviation of the word cattle gut. Gut strings are made from sheep or goat intestines, in the past even from horse, mule or donkey intestines.

Otherwise it could be from the word kitgut or kitstring. Kit meant fiddle, not kitten.

I suggest that you go to MIMF, and read Todd Stock's post on using SSII. Says it all! It works best when allowed to dry, for many reasons.

_________________
Waddy

Photobucket Build Album Library

Sound Clips of most of my guitars

Hesh:
I wish that I had heard about aluminum foil turning koa green last year.
It confirms my experience.

Bob

I use SSII so after reading your post, I looked up the MSDS. I'm wondering if you are referencing a different one than the one I found which indicates that SSII is pretty benign overall.

Section Three--Immediate Health Hazards
• Skin absorption: No hazards known.
• Ingestion: Not expected to be harmful under normal conditions of use
• Inhalation: No hazards known
• Skin: No hazards known
• Eyes: Causes irritation

Section Five--Fire and Explosion Hazards
Combustible. Keep away from heat and flame. In case of fire, use water spray, dry chemical, foam or CO2. Use water to keep fire-exposed containers cool.

Section Six--Safe Handling and Personal Protection
No special protection necessary.

That said, I follow the manufacturer's instructions and, after applying SSII, blot the sides overnight between paper towels under a weight before bending them on my hot pipe. At that point the wood is no longer wet from the SSII. Because of the instructions, it hadn't occurred to me to try bending the sides when wet with SSII. I wouldn't want to breath the vapors anyway just on general principles. Good to know that it's combustible. Also good to know that the MSDA says the storage life is one year at 77 degrees.

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Once in a while you get shown the light in the strangest of places if you look at it right - Robert Hunter

It's easy to remove the green or black stain that is common when bending koa and mahogany. The stain is from the ferrous metal oxidation of the slats. I use Whink Rust Remover diluted 50-50 with water and a spray bottle. The stain disappears almost immediately.

http://www.whink.com/index.cfm?fuseacti ... uctID=4328

Mike Franks
www.mjfranksguitars.com
www.facebook.com/mjfranksguitars

Has anyone tried using any other brand of veneer softener? Supersoft isn't available north of the border, as far as I know.

Alex

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"Indecision is the key to flexibility" .... Bumper sticker

Alex - I get SSII ordered into Canada from Veneersupplies.com. Once again its much cheaper to ship to a hotel in the states while visiting than it is to ship across the border. This past summer while in Seattle I picked up a gallon which should last me a very long time.

FWIW - I bend on an iron and since using SS I find the bending process to go much easier for ALL woods. I soak the pieces about two hours prior to bending. Then when complete I spray both sides again with SS and clamp into the outside mold and leave overnight. The next morning nearly all bumps and imperfections are gone. Sure this might be all a little overkill but it's working for me.

_________________
Doug

Don't let fear or common sense stop you from trying to build something

Just to Let everyone know that I haven't blown up and my lungs haven't collapsed . Colin, I'd forgotten about the info you'd sent me . John, Thanks for the specific advice, didn't have the nerve to go so hot but went up to 150 degrees Celsius and the bends are nicely set with little springback and minimal staining. I used aluminium slats and greaseproof paper between the blanket and the wood. Thanks all.

J De Rocher, just an few comments.
As you quoted, (Flash Point: ~91C )
And to quote you,
MSDS sheet does also say [/quote][/quote] so there is some good common sense in following instructions and also not wanting to breath the vapours.

_________________
The name catgut is confusing. There are two explanations for the mix up.

Catgut is an abbreviation of the word cattle gut. Gut strings are made from sheep or goat intestines, in the past even from horse, mule or donkey intestines.

Otherwise it could be from the word kitgut or kitstring. Kit meant fiddle, not kitten.

Mike, glad you were successful with the bending, must have felt good

_________________
The name catgut is confusing. There are two explanations for the mix up.

Catgut is an abbreviation of the word cattle gut. Gut strings are made from sheep or goat intestines, in the past even from horse, mule or donkey intestines.

Otherwise it could be from the word kitgut or kitstring. Kit meant fiddle, not kitten.

Thanks Doug. I'm going to get some veneer softener from A&M Wood Specialty in Cambridge, and give it a try on some practice pieces first. Shipping to a US hotel is a good idea. I've got cousins in Michigan, so I could have stuff delivered there, and have a visit.

Alex

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"Indecision is the key to flexibility" .... Bumper sticker

Alex, I had a gallon shipped to Windsor, and the shipping was the same as the cost of the SSII. But still worth it when you consider a the cost of a broken expensive side.

Bob

Certainly did, bent a stack of solid linings now too.

If koa and black acacia turn green during bending while wrapped in aluminum foil, the discoloration must be due to something other than ferrous metal oxidation, surely?