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| Martin Side Cracks http://mowrystrings.luthiersforum.com/forum/viewtopic.php?f=10101&t=54167 |
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| Author: | Mike OMelia [ Sun May 23, 2021 5:38 pm ] |
| Post subject: | Martin Side Cracks |
This one is pretty bad. Looks like someone used it like an axe. Is it repairable? I’ve got it in a humidity bag. Lots of motion in the fractured parts. If it is repairable, cost? Repair finish? Mike |
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| Author: | profchris [ Mon May 24, 2021 3:50 am ] |
| Post subject: | Re: Martin Side Cracks |
I'd say definitely repairable, assuming none of the bracing was damaged during the bar fight  Even I could glue up those cracks so they would hold together and make the side structurally sound.Repairing it so the damage is barely visible is another matter - I've seen repairs which achieved that, but that's a high skill level and time consuming, thus expensive. |
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| Author: | bluescreek [ Mon May 24, 2021 5:26 am ] |
| Post subject: | Re: Martin Side Cracks |
I am a martin repair shop yes this is repairable looks like a bad drop |
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| Author: | Chris Pile [ Mon May 24, 2021 8:03 am ] |
| Post subject: | Re: Martin Side Cracks |
I've fixed worse. It won't be easy, but it's doable. |
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| Author: | Terence Kennedy [ Mon May 24, 2021 8:42 am ] |
| Post subject: | Re: Martin Side Cracks |
An issue I see is the upper crack is pretty close to the bottom edge of the kerfed lining so that there may not be a ton of room for a solid cleat inside. How do you folks deal with a crack right along the edge of the lining? |
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| Author: | Cal Maier [ Mon May 24, 2021 8:48 am ] |
| Post subject: | Re: Martin Side Cracks |
Those cracks were not caused by a lack of humidity, probably not good to bag it. Looks like what John said, possible shipping damage can do that too. Completely repairable, but will be a bit of work, finishing will be the easy part. Cost? Time = $. |
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| Author: | jfmckenna [ Mon May 24, 2021 8:51 am ] |
| Post subject: | Re: Martin Side Cracks |
You should see the one I'm working on now!  As mentioned, yes repairable. I like to use HHG but AR glue works well too. Make some spool clamps. The hardest part is aligning the two parts together. Sometimes they go together easily but they can move when clamping up too. A tuner clamp with a cleat on the inside will align everything perfectly before you clamp tight with spool clamps. |
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| Author: | Chris Pile [ Mon May 24, 2021 9:14 am ] |
| Post subject: | Re: Martin Side Cracks |
Quote: A tuner clamp with a cleat on the inside will align everything perfectly before you clamp tight with spool clamps. Exactly. Easy to make, too - so make a couple. I used old cheapies from the parts box. As for hiding the repair, touching up with fine artist brushes to make it look like grain or figure, then covering in clear works well enough to fool the eye of most folks. |
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| Author: | bluescreek [ Mon May 24, 2021 9:33 am ] |
| Post subject: | Re: Martin Side Cracks |
I no longer use tuners for clamps rare earth magnets are more controllable With todays adhesives this can be done and may hardly show I fixed my share of these. I would estimate about a $400 repair for glue and finish touch up |
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| Author: | Clay S. [ Mon May 24, 2021 10:00 am ] |
| Post subject: | Re: Martin Side Cracks |
I glued some neodymium magnets into small blocks of Corian which I then glued to strips of cloth to make flexible clamping cauls. I use across the grain veneer strips instead of individual cleats to reinforce the repair. I took my inspiration from TJ Thompsons crack repair tools, but wanted to make something flexible for doing side cracks. I put tape on the cross grain veneer strip to both hold it together and to prevent it from gluing itself to the caul. |
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| Author: | jfmckenna [ Mon May 24, 2021 2:03 pm ] |
| Post subject: | Re: Martin Side Cracks |
How many magnets do you stack up to make it strong enough to pull each half of the cracked sides together? |
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| Author: | Mark Mc [ Mon May 24, 2021 3:06 pm ] |
| Post subject: | Re: Martin Side Cracks |
Clay - that is a brilliant idea, and perfectly illustrated in the photos. Love it. It makes me want to go and break a guitar just to have the fun of putting it back together again with that jig. |
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| Author: | Clay S. [ Mon May 24, 2021 6:16 pm ] |
| Post subject: | Re: Martin Side Cracks |
jfmckenna wrote: How many magnets do you stack up to make it strong enough to pull each half of the cracked sides together? Additional magnets can be stacked on the back of the outside strip to increase the force if needed to align the cracked side, just as you would do with individual magnets. |
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| Author: | Mike OMelia [ Mon May 24, 2021 9:01 pm ] |
| Post subject: | Re: Martin Side Cracks |
Clay, how do you keep the individual magnets from attracting each other? |
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| Author: | Mike OMelia [ Mon May 24, 2021 9:01 pm ] |
| Post subject: | Re: Martin Side Cracks |
Oh, and does anyone have a reliable magnet source? |
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| Author: | Clay S. [ Mon May 24, 2021 10:50 pm ] |
| Post subject: | Re: Martin Side Cracks |
Hi Mike, The magnets are oriented so they repel each other on the strip and are attracted to the other strip. Here is a link to a discussion Barry Daniels and I had some time back, where he demonstrates Thompson's magnetic caul system, and we discuss the possibility of making flexible magnetic cauls. It also shows some of the nice repair work Barry does: https://www.mimf.com//phpbb/viewtopic.php?f=8&t=6381 You can find small neodymium magnets on Amazon and many other places, but you may want to buy them while you can: https://en.wikipedia.org/wiki/Neodymium_magnet_toys ![[headinwall]](./images/smilies/headbangwalluf8.gif "Mad")
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| Author: | Colin North [ Mon May 24, 2021 11:57 pm ] |
| Post subject: | Re: Martin Side Cracks |
Clay S. wrote: --------------- You can find small neodymium magnets on Amazon and many other places, but you may want to buy them while you can: https://en.wikipedia.org/wiki/Neodymium_magnet_toys Dangit, got some shopping to do. |
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| Author: | bluescreek [ Tue May 25, 2021 5:33 am ] |
| Post subject: | Re: Martin Side Cracks |
not all magnets are the same I like the 1/2 in think ones , they have better pull. They have round and square. Find some that give a good 10 to 15 lbs pull |
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| Author: | Mike OMelia [ Mon May 31, 2021 3:11 pm ] |
| Post subject: | Re: Martin Side Cracks |
I have been studying the cracks. There is one place where there is a gap. Luckily I found that piece inside the body. I need a pro to estimate this cost. I think I have everything I need to do it. Will require finish work. But it looks like a big job. How much? |
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| Author: | jshelton [ Mon May 31, 2021 5:16 pm ] |
| Post subject: | Re: Martin Side Cracks |
Mike OMelia wrote: I have been studying the cracks. There is one place where there is a gap. Luckily I found that piece inside the body. I need a pro to estimate this cost. I think I have everything I need to do it. Will require finish work. But it looks like a big job. How much? Bid way higher than what you think it will cost, if the customer doesn't leave immediately that's a good sign. I always give customers a range, "this will be $500-700" and wait for a response. If you decide to take it on, figure out how much you are worth per hour and keep track of the hours you work on it. |
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| Author: | Clay S. [ Mon May 31, 2021 6:44 pm ] |
| Post subject: | Re: Martin Side Cracks |
I think John Hall gave you a pretty fair estimate of the cost anywhere east of the Mississippi (with the possible exception of NYC). |
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| Author: | Woodie G [ Tue Jun 01, 2021 6:28 am ] |
| Post subject: | Re: Martin Side Cracks |
If not already mentioned, the order in which these cracks are repaired will have a big impact on getting it all lines up again for a successful repair, and this might take a bit to figure out. In some cases, I have had to glue the fractures closest to the top and back along the linings to pull those portions of the side back into shape, then work the remaining crack in the middle of the side. Having some flat steel pieces, magnets set in flat plywood or MDPE cauls (with ply faced faced with package tape or similar non-stick surface) on the outside of the guitar can help provide a reference surface against which to line up the broken bits. We used to use a $25/inch estimate for crack repair, although splining top cracks was an exception that generally ran the cost up above that rough estimate. |
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| Author: | bluescreek [ Tue Jun 01, 2021 8:39 am ] |
| Post subject: | Re: Martin Side Cracks |
There are many ways to do this. If the cracks close tight I find the best glue is west systems 3 epoxy. No cleat needed and you have plenty of open time. This also fills gaps well . Depending on the crack some can cost more than others for sure. With grain cracks are easier than cross grain. This is a great topic and we can see how many ways the same result can be achieved. The one trick is clamping. Not only as mentioned , that we want a flat repair , I find 3m tape is wonderful as it stretches. The other thing is can you do multiple cracks at the same time or must we do one at a time. As Woodie mentions you have to find the logical sequence to get all cracks to close to the best of your ability. Here are some techniques that can come in handy https://www.youtube.com/watch?v=I30u4zd3eKA |
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| Author: | Mike OMelia [ Tue Jun 01, 2021 3:44 pm ] |
| Post subject: | Re: Martin Side Cracks |
My apologies to John Hall, I missed his estimate. Turns out that was what I was thinking. Most of the cracks are simple. One however is "lipped" under and I am unsure how to pull it apart to re-seat. One of those screw jacks? Mike |
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| Author: | Mike OMelia [ Tue Jun 01, 2021 4:35 pm ] |
| Post subject: | Re: Martin Side Cracks |
Is this about right? I have sourced some corian. 1" thick. https://www.first4magnets.com/us/circul ... ps_1_17357 Magnets above are 1/4" thick. Or should I go with 3/16" thick? Lol! https://youtu.be/0t8yDnyOaQ8 |
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