Claude Caruana
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Here is a long overdue update on the repair! It took long as I was loothing in my mentor’s workshop back in Spain for a few weeks. I also wanted to get some feedback from the owner a few weeks after handing over the repaired guitar.
The epoxy worked wonders. In the end, I worked with a combination of West System G-Flex and 105/206. I used G-Flex wherever I could, but the 105/206 worked better in some tight spots as it flowed better through the cracks. With the use of 105 I avoided the need to remove a section of the binding/purfling.
With a camera on the inside, I kept injecting epoxy until I could see it oozing out from the bottom of the kerfing blocks which were still attached. The inside got a bit messy but I guess this is unavoidable.
Once that cured, I added some further epoxy from the inside with a syringe to further stabilize the joints, and also to glue the blocks which had gotten completely detached.
The new piece of cedar was glued using titebond. Here is where I in hindsight I should have paid more attention on matching the cedar. All seemed pretty close before I put the piece in, but once it, it really stuck out like a sore thumb.
After some research, I opted for a set of shellac touch up colors from Kremer in Germany. This was not the best choice and in retrospect I should have gone with dyes (Stewmac Colortone or Oldwood dyes which are more readily available in Europe). The Kremer shellac pigments would have been great for localized touchups (cracks etc.. But not to cover a relatively large area)
The structural part was straightforward and all went well. What I grossly underestimated (even after the many references to this in Ian’s video) was the cosmetic part. It was a headache to match anything. I tried to apply it using an airbrush – ok for color but it was completely the wrong texture. Finally I went across the grain with some sandpaper and created some artificial medullary rays. Initially I was trying to build up color, but in the end, it seemed like it worked better backwards where I over applied the color then sanded it down until I more or less matched the rest. I think the finish still leaves much to be desired, but I did warn the customer multiple times that it is NOT going to be unnoticeable.
Next came Gluboost over the new cedar plus some of the old. Gluboost worked really well and I was very happy with the way it blended into the poly finish.
Smoothing was done with 3M Gold up to 800 grit, then with micromesh up to 12,000. Final buffing was done using Menzerna 2500/3500 (I love this polishing compound. Comes from Germany and I consider one of the best of the ones readily available in Europe) and an orbital polisher.
In the end, the client was happy with it. Emphasizing the cosmetic shortcomings from the start, I think, helped a lot in setting the right expectations.
I charged for 4 hours of work (in reality it took me way more but I think 4 hours was a good reflection on how long it should have taken if I had prior experience and did everything right from the start)
Takeaways :
– Prior to talking to Ian, I would not have considered using Epoxy. It was a great learning where, when and how to use Epoxy.
– Great experience with West System Epoxy. I did a lot of tests prior to getting it on the guitar, and none of the other brands I tried so far match the adhesion properties of West System.
– Most of the work was on the cosmetic side. I need to pay way more attention to this in the future and plan it out better from the start.
– Matching the run-out was something I did not give enough attention to. In hindsight, it’s obvious : mismatches are further worsened, not improved, once the finish goes on. I really should have been much more careful with matching the unfinished cedar right from the start.
Thanks again Ian and the Looth Group for your invaluable help!
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Thanks so much for this, Ian.
As discussed, the epoxy I could source relatively easily is the StewMac from Madinter.
StewMac Stewart-MacDonald Epoxy, Slow setting, clear
I checked our local Amazon, but it seems to be pretty much an extension of what you would typically find at a hardware store.
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I’m planning to start it on Friday. Unfortunately the Stewmac epoxy i ordered came from a bad batch and didn’t cure properly on testing, so I had to abandon that one. I did however manage to find West epoxy in Europe from a boating supply store in Hamburg. Explore epoxy resins & hardeners now | TOPLICHT. It should be arriving tomorrow!
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Here you go 🙂 Chatoyancy – Wikipedia
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That would be amazing, Ian! Let me know what we need to do to organize that
