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SSII is a great product but the bend set problem will bot be solved by using SSII. Do you have pictures of your upper and lower bout bending cauls? Somewhere the heat is not setting the bends in the bout. that tels me the heat is getting to the wood in the bouts properly

Michael, You can see the cauls in the picture of the meter they are in the back ground but if you want to get a better look I can get them for you in a few minutes.

Some Mahogany can be a bear to bend and may show considerable springback.

Can you try this with some Indian Rosewood and then report back.

Cheers

Bob

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Bob Connor
Geelong, Australia

Yeah, if you send me some.

Since I switched to two blankets I've had very little springback. I had problems before. I pretty much do it like John Mayes in his videos. I go blanket/spring steel(covered with Al foil)/moist craft paper/ side/ moist paper/spring steel/blanket. Clamp it all together with spring clamps. Start the bend when I see a lot of steam (around 265) Usually finish around 320-330. Thermometer is between the top blanket and steel slat just behind the waist caul. Cook around 300 for 10-15". Cool fully and reheat to 300 for 10". Cool overnight.
After lots of different techniques the above has been the best by far. Sides come out looking great. I think the two blankets really dry out the wood.
Terry

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It's not what you don't know that hurts you, it's what you do know that's wrong.

What happened with one blanket? It seems I'm doing the same as you did but with one blanket and no re cooking. Could it be the re cooking that sets the bend?

That's the idea!

Chris buddy everyone has some good points here and we all seem to agree that the bend is not setting correctly.

SuperSoft II won't help you as Michael indicated and I will add that these sides should be able to bend without it. Although it might help many people have bent sides without it for years. It's a great product and I plan on trying it the next time I am bending something expensive but it's a good idea to get your chops down first without it.

The baked straight idea is interesting. With that said if you do try the method that I use and learned from others here perhaps use a fresh side? You might want to ask some of our sponsors if they have any orphan sides, they usually do since we all are such good benders.........

Also it's really important that the stack is clamped firmly and letting the blanket make even and complete contact with either a slat on the wood or the wood directly if you do it that way which I don't. I use the same blanket and controllers that you have and about 2-3 minutes is all it takes for my stack to heat up enough to start bending. Note the spring clamps on both ends of the stack.

BTW you can iron your sides flat if you don't want to wait for new wood and try again with another method. I am just a little concerned that these sides have been through the ringer and may break when what you do next would have indeed worked with a virgin side.

You have 2 things going against you. The pattern is most likely acting like a heat sink. The other is the wood. There are times Mahogany is just too brackish to take a good bend but I think in this case you are not getting the heat into the wood. Your pattern may be acting like a large heat sink and robbing the heat off the wood you are trying to bend.
In my tutorial you should have all the bending complete within 4-6 minutes. I still run a 15 minute setting cycle. I didn't see Todds video but I would like to . The heat should not be an issue with the blanket , if you are seeing over 350 degrees. I also don't think you need all that wrapping. Also don't use much water. Maple and hog prefer heat with little water. If you need to call me I will be in the shop and maybe we can get you bending
john hall
blues creek guitars

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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

The baked sides seem interesting but it would seem that it isn't the problem since T. Kennedy uses the same times with two blankets. I have been clamping the package together with wooden clothes pins, 3 down each side which works really well and I have plenty which I use to glue on kerf lining with.
Edit: Thanks John, I read over your artical from the link here. I may give it another try tonight with a fresh side as I have 7 more practice pieces left. They are 8" wide and I'm thinking of splitting them in half to 4" instead of cutting them to 6" to get more practice pieces.
Do you think if the blanket was on top that would maybe solve the problem? The thing is I think Todd's pattern was solid too but his blanket was also on top.

I would pay attention to John Hall and call him too - his method is how I learned to bend.

Spring clamps, the orange 3" ones from the Borg or where ever you can get them are much stronger clamps than clothes pins. I think that the clothes pins are also suspect in not keeping your stack firmly together keeping the heat concentrated.

The heat sink idea is what I thought too and I think it's a contributing factor.

I'd call if I had a cell phone or long distance on my land line. I usually get by with the internet or 800 numbers. I got rid of my cell because I wasn't using enough minutes for $50 bucks a month. Got to save that money for tools and practice wood.

I had more springback with one blanket Chris, and cracked a couple of more figured mahogany sides. Things are much better for me with two.
Terry

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It's not what you don't know that hurts you, it's what you do know that's wrong.

The point I was making is that it may not be your technique.

It may be the wood you are using

Bob

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Bob Connor
Geelong, Australia

I have been bending on average 6 sets a week for about 7 years. Todd I would love to see you video . There are times that mahogany is just too brackish to bend. I don't use much water at all but I bend fast when the temperature is where it needs to be. Most people either take too much time to bend or pull the wood too fast.
I agree with you Todd , 1 blanket is all you need. Wood has no idea where the heat is coming from , only that the heat is there. My tutorial goes into pretty exact detail of what I do and how. The one thing , is if your wood is still damp when you pull it you may be using too much water or not enough drying time. There has been some good advice here. Some of us use different techniques than others but I know Todd and Hesh, we all have been doing this a while. I suspect your heat or the wood. Here is my basic technique
the sandwich is steel wood steel on the top is the blanket.
I dampen the wood with water and I don't saturate it.
I will allow the heat to rise to 250F and at that point to the lower bout. The upper bout is next followed by the waist. this takes on average about 4 minutes.
I will allow the heat to rise to 375 and hold that for about 1-2 minutes. I will then hold a 15 minute drying cycle of 200 to 220 F and allow to cool. Yesterday I bent bubinga ( 420 degrees ) but for the most part the basic technique is followed. Good luck
john hall
blues creek guitars

_________________
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

"Good Morning OLF!"
Well I bent another side last night and changed a few things to see if it will make a difference. For one I put the blanket on top and that did seem to make the tempreature rise quicker then when on the bottom. I also still used the foil and craft paper but instead of dipping the paper in water I spritzed it on both sides and I also spritzed the side too. Just enough to wet it like I was washing the windshield on my bike. The stack is from bottom: slat/foil/paper/wood/paper/blanket/foil/slat. Rock, Sissors, Paper. I did get steam quicker and I checked for the hiss when touched with a wet finger at lower, upper bouts and waist.The temp was at 290ish. I followed the same bending order and when set the temp was 320 and I let it go to 330 and backed it off to 300 and let it cook a little till 12 mins. had passed and then turned off the blanket. After an hour I hit it for 3-4 min. and watched Charlie Rose and went to bed. At 8 this morning I backed off the waist a bit and while holding the lower slat down noticed the waist raise about 1/2" so I put the themocouple in between the caul and lower bout peak and set the waist again and cooked it for 20 min. The temp went to 330 and kind of stayed there and I backed it off to 300 again. That's got me wondering if maybe the wooden waist caul might be acting somewhat as a heat sink too. Maybe I'll replace it with Alu. bars or pipe later on. I don't know yet what the end result is going to be as of yet. I was thinking of removeing it around noon. Just giving you all an update. I have to say thanks again to every one. I didn't expect a whole lot of responce being that yesterday was the 4th. Thanks again for the help.

Here's the side.

Okay, I'm gettin close. I'm thinking that putting the blanket on top might have been the big change. And maybe water. What's your thoughts? I may try the next one back at the original times to see what happens. The waist did seem to rise like it did before the last cook so maybe that wasn't needed and may have caused the scorch on the upper bout. I gusee that is water stain on the inner waist.

I also noticed that when I set the waist that it has a tendency to straighten out the curve behind the waist to the peak of the lower bout. I'm wondering if I should make a 3rd caul to hold tha flush to the pattern as to let that re curve or S curve set. If you look close to the mold picture I think you can see what I'm talking about. I see where Hesh uses a 3rd caul. I guess he'll be chiming in soon enough.
Oh yeah, I have another discussion on mineral deposits that show some Jacaranda that I remembered I had after Bob ask about rosewood. Anyone have an idea how that might bend? It's pretty dry and stiff. It's a rosewood but I don't know if it will bend like EIR.

Good job Chris!

This tells me a few things too.

First the I am pretty sure that the bend was not setting prior for you for a number of reasons - all discussed here prior too.

When I switched to using my blanket on the top I also had to extend my warm-up time by about 30 seconds. Heat rises, at least on this planet..... so with the blanket on the bottom you actually had a better shot at setting the bend in your first attempts. But on the other hand the solid form that both John and I believe may be acting like a heat sink is under the wood with the blanket on the bottom which should have heated the wood better but it didn't. With the blanket on the top the solid form can still act as a heat sink but not without the heat of the blanket being drawn through the side first. I don't like that the form is acting like a heat sink for a number of reasons but most of all your blanket is on for over 1/2 and hour....... No carbon credits for you...... Again it only takes me 4-5 minutes of blanket time to bend a side.

I also think that the waist caul being made of wood and not covered in metal is acting like a heat sink and wicking away your heat.

I don't know if you did anything different this time to keep the stack clamped together tightly but this will greatly help too.

The addition of a little spritz of water seems to have helped as well. Again this tells me that the side was not getting bent originally regardless of how long the blanket was on and considering the other concerns mentioned.

I only use foil OR craft paper and usually craft paper - I see no reason to use both. You want the very little moisture that you use to create steam, soften the wood, and then evaporate away to prevent cupping. The additional foil layer does not dissipate the moisture as well as simply using craft paper will.

Starting at the waste and leaving the last 1/2" for the final step, doing the lower bout, then the upper bout, and returning to waist to tighten the last 1/2" is how many, many folks bend a side. I learned it from John.

The use of the third caul is optional and not necessary. I started doing this when I had some very difficult wood to bend that wanted to cup on a "rope" figure. My friend Matt Mustipick also was working with the same wood and had the same cupping on the rope figure. It was his idea to use a third caul and it worked for me when I tried it. Since then I always use a third caul just to help keep everything tightly against the form but again I don't think that it is necessary.

I think that you have learned a bunch from your efforts. If it were me I would now move to fix anything that was not right with my method or equipment. I am concerned about your solid form but think that it's probably something that you can use but you are going to have to figure out your own new times and temps and not use mine if you do use the solid form. I would also get some spring clamps for the ends and make or retrofit the waist caul so that it is metal or covered in metal.

My bender is from John Hall and has open forms that he sells separately and you may want to consider purchasing one from him or making a new form.

These toots and video are the methods that work for the author. Todd has in the past called them "one method" because that is exactly what they are - one method - there are many methods and many methods work for the user and with the tools that they use. Guitar building is no place for a cat because there are a thousand ways to skin most every cat in guitar building.

When you work from someone's method it's important to be as precise as you can and follow their recommendations exactly at least the first time. That is of course unless you have your own method. Right now I see you in uncharted territory using bits and pieces of a number of methods and you really don't even know what to expect yet having not successfully bent very many sides. This is said out of friendship and concern and not intended to be rude what-so-ever.

So my suggestion my friend is to stop introducing variables and work as closely to one person's method and tooling as possible and see how it goes for you.

Yep that makes complete sense to me but I prefer to have the slats that contact the wood be stainless in as much as the increased flexibility helps prevent breaking a side getting it out of the bender. I use a third slat, spring steel at the top of the stack to help concentrate the heat of the blanket below on the stack and not let it radiate upward and outward as quickly. When I release the waist caul to take the side out of the bender the spring steel slat being on top is not an issue but if it were under the bent side more care would need to be taken as it would spring back to straight more so than a stainless slat.

The pattern is held together with 4 -3/8" oak dowels so that it will break down and fit inside the outside mold for storage. I designed the bender press for removal for storage also. So I could easily make it an open pattern and use the filler pieces to make spreaders for the mold. I have another rib in the oven now and I made up a quick 3rd caul to hold the spot I was concerned with down. I've been trying to stay with Todd's system and was with the exception of the blanket on the bottom but I had ask Todd about that earlier and we thought that it would probably be alright but it turn out the other way as far as I know now. I went back to Todd's times on this bend to see if it will work with the blanket on top now. I'm working on getting this down and by no means take any advice the wrong way. I think we all are learning somethings here, me more then others. But that's what these forums are all about don't you think. It's not about being right.

I think I'm there or at least rounding third headed toward home.
Although it looks like some dark spots on bout it's just the lighting and no scorching. I used Todd's times and tempreature. I continued to spritz paper and rib, both sides, instead of dipping paper . Seems it lets me have a little more control of the amount of water applied. Very little spring back at the ends as you can see in the 1st. photo .

I'll probably look into changing the press caul to maybe a piece of conduit to match the waist curve or possibly a fitted open caul with a stainless cover made from the crop end of my slats. I might go ahead and use a second blanket on the bottom as a spacer since I have a bad blanket and the form was cut for a blanket on the bottom. I also will look at converting the form into a 3 section form leaving the full section in the center which will open it some. Thanks again everyone.
Is there a spell checker here?