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OK !!! all was going sooo great, just finished my secont mold i made from "Michaels SJ". was happy as a clown, and then I put the sides in the mold, Didn´t have anything to press the sides against the molds contour, so I shaped the leftover contour from the inside and gently pressed it down, like the stew mac cardboard. all went fine, allthough the inside counrour-shape was at the bottom of the mold inside the sides, (16mm MDF) then I took my finger on the side to see that it was not any tension on the sides and then CRAAAAAACK /&%€%&&/()&)"!"#€!€#. Grrr. wont use any bad language in here, but I can tell you words came I didnt think I had in me . so now I am not sure what to do. no chance to fix the side, its was past repairs, well not after I had my say with it. the crack was like 40cm long "before I made 2 pieces of it" buhu. so now I guess all I can do is get me another set of perhaps its possible to just get 2 sides (so they will match). ??

Lars.

Lars, I'm sorry to hear about that. I know how upset you must have been.

To clarify, were you putting the pre-bent sides from stewmac into the mold for the OLF SJ you had just made? Were the sides pre-bent for that design?

I would contact stewmac about another set of sides, or maybe someone has some orphaned sidewoods of the same wood.

Darrin

they were prebent for the OLF SJ "michaels" and the mold had a pefect shape, perhaps I had let the sides lay to long without a proper mold for to long "2-3 weeks" I dont have a clue ! . I´ll go down and take a photo to show you all the mold.

Lars

Lars, it is possible that during the trip to your shop and the following weeks the sides "relaxed" and straightened out enough to resist being bent back into the SJ shape. Thus the crack. On the other hand, the crack could have been just waiting to happen. It is natural for sides to straighten out some or at least want to.

You should touch up the shape of the sides on a bending iron or the like to get prebent sides to conform to your mold without stresses.

Thanks steve, good to know, wish I had known it earlier though, hmm. well all things happens for a reason ! I will for sure do that on the next though ! . as you can see I have the template inside the mold and the shape itself is perfect contoured.

Lars

just an update. our friend the Zootman is looking to see if he has a good match for my back, so I am feel goo now . It was a not to pleasent feeling to have the darn thing crack on me. haha

Let me guess the crack started at the end of the side (butt neck or both) directly above where the mold was supporting the sides. Yep the problem is with no support the spring tension on the side started the crack and it traveled rapidly along a grain line.

If you had caught it soon enough you could have prevented it from going too far and glued the crack in place and got the end blocks glued all would have been fine.

In the future get your end blocks glued up as soon as possible and this will not happen. or support the out side of the ends with a thin but stiff shim piece of wood equal in height to the sides at the ends between the mold and side ( side will be slightly over tensioned at this time) this prevents the ends from spring out where previously it was unsupported.

This should probably be transferred to the Kit Builders section. Michael, that is a great piece of advice for kit builders to know. It will probably save someone else from the same issue. Seems like the instructions should include that info, or it should be taped to the side with a big "Caution" in red.

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Waddy

Photobucket Build Album Library

Sound Clips of most of my guitars

I would think you need to have the ends totally supported, my first mold was a Kinkead style, so the entire guitar sides fit in the mold. Sorry to hear that Lars, I think you need some 'inside side hold mold formers' to hold the sides in, using the entire width is maybe not a good idea.

Eh, I ruined a set of sides bending, a set of sides in the safty planer, near complete box of my own design, a top....I always wonder what is next... ....

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Here is what a Parlor Guitar is for!
http://www.youtube.com/watch?v=oEa8PkjO6_I

So this height mold you speak of mold was use only till you glued up the end blocks? If not how did you profile sand and or glue on the back or top assembly?

You raise it out of the mold using wood spacers, you can still profile sand, but the mold is heavy. Use the inside mold formers to hold it.

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Here is what a Parlor Guitar is for!
http://www.youtube.com/watch?v=oEa8PkjO6_I

this is my technique
http://bluescreekguitars.com/blog/
I think in this case Lars you may have learned the hard way but still , if you learn something out of this it isn't a total loss. The side set may still be salvageable , I have repaired sides that were split as bad if not worse and you would never know it. Look at this as an opportunity to learn a repair technique.
john hall

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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 mold had holes drilled on the inside about 1 1/4" up to take stop blocks so that the top of the guitar is raised out of the mold this is the style I use as it it from the Kinkead book which I'm building my OM

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Formerly JJH

I learn more from my mistakes than my successes

Hei Lars,
sorry about your mishap! I have to agree with John Hall though, you probably could have saved that side if all it did was split, but as I understand your first post you broke them (as in, fractured them across the grain in anger and disgust), correct? That makes it harder...

Chalk it up as the first in a long row of "oh well"s, if you keep building it won't be the last. As they say, the only people who don't make mistakes are the ones who don't make anything!

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Rian Gitar og Mandolin

From the picture, it just looks like it split along the grain. You can probably just glue it back together. Once assembled with the side reinforcements, I suspect that it would be OK.

What I do is make two identical molds that stack on top of each other and pin together. Each mold works on its own, but for certain operations where I want the full height of the sides supported, I double it up.

The sides in your photo have obviously sprung back a lot. I wouldn't try to build with them like that. I'd work them on a hot pipe and make them fit the mold.

I think John and Alan are right that you may be able to glue that side back together invisibly.

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Todd Rose
Ithaca, NY

https://www.dreamingrosesecobnb.com/todds-art-music

https://www.facebook.com/ToddRoseGuitars/

Lars, sorry to hear about you incident.
Lot's of tips offered here and give another one or two. After bending store you sides clamped into the mold to help hold the shape until your ready to install the blocks and linings. The sides need to be dry to do this or they'll cup if they're damp. Another trick is to tape the sides end to end pulling the end toward 0ne another, this will also help them hold their shape.
I prefer to clamp mine into the mold, but taping is much better than nothing.
Hope you can find a good match. Keep us posted.

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Jim Watts
http://jameswattsguitars.com

Lars, sorry to hear about you incident.
Lot's of tips offered here and give another one or two. After bending store you sides clamped into the mold to help hold the shape until your ready to install the blocks and linings. The sides need to be dry to do this or they'll cup if they're damp. Another trick is to tape the sides end to end pulling the ends toward one another, this will also help them hold their shape.
I prefer to clamp mine into the mold, but taping is much better than nothing.
Hope you can find a good match. Keep us posted.

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Jim Watts
http://jameswattsguitars.com

Thank you all for reading, and giving these great advices.
Michael, yes that´s just how it happened.
Unfortunately, after it first cracked,about 20cm I stupedly enough took my hand and ripped it all the way through . hmm !! . But like you guys said, its a good learning ! I will see if I can glue it together and how it will look, if not for keeping but as a training for repairs. Although I have spoken to Bob Celafu and he´s checking on if he´s got a good match for the back. .
Have also ordered spreaders to go inside the mold from John H.

PS. what kinda glue are recommended in these situations ?

Lars.

Sorry to hear about your crack up Lars. I like to make a side and binding "holder" to keep the shape
until I'm ready to glue in the end blocks. I think Titebond would be fine for gluing the crack.

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Anderson Guitars
Clearwater,Fl. 33755

Lars, I would think that pretty much any wood glue would work to repair the split. I generally use LMI's white "Instrument Makers Glue". Just spread a thin layer along the split and use binding tape to pull it together. If you are careful in lineing it up, you shouldn't be able to see the split after the glue dries.

Dave....I usually put my sides in the mold after they are bent, but I like your jig. That would let me bend more than one set and keep them braced until I could get them glued up. Thanks.

Sorry for the double post, I don't actually know how that happened.
Dave - I like your side holder I may have to do that.

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Jim Watts
http://jameswattsguitars.com