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| What percentage does thin CA shrink when curing? http://w-ww.luthiersforum.com/forum/viewtopic.php?f=10101&t=16641 |
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| Author: | Sheldon Dingwall [ Sat Mar 29, 2008 2:00 pm ] |
| Post subject: | What percentage does thin CA shrink when curing? |
Anyone know how much thin CA shrinks when curing? I've never run across that spec. |
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| Author: | clavin [ Sat Mar 29, 2008 2:06 pm ] |
| Post subject: | Re: What percentage does thin CA shrink when curing? |
It depends on the brand. I used Stew-Mac's and found it seemed to constantly shrink to the point of frustration. There was just no controlling it. After speaking with Larry Robinson and a few members here that use it I switched to Star Bond and have loved it since. I notice almost no shrink, and it has a 2 year shelf non-refrigerator life span. Why worry about any other type? Rio Grande sells it I believe it's just as much as the other brands. Craig L |
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| Author: | Michael Dale Payne [ Sat Mar 29, 2008 3:32 pm ] |
| Post subject: | Re: What percentage does thin CA shrink when curing? |
A good quaility CA Like Star will srink about 2-5% depending on the viscosity and enviro mential conditions. |
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| Author: | Parser [ Sat Mar 29, 2008 9:58 pm ] |
| Post subject: | Re: What percentage does thin CA shrink when curing? |
the thin stuff sucks right into pores really easily..why are you concerned about shrinkage? |
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| Author: | jhowell [ Sun Mar 30, 2008 9:09 am ] |
| Post subject: | Re: What percentage does thin CA shrink when curing? |
Craig-- Thanks for the tip on Starbond CA. Just went to a site that carries it and was amazed at the range of product available including reasonable prices on black. |
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| Author: | Bob Garrish [ Sun Mar 30, 2008 1:12 pm ] |
| Post subject: | Re: What percentage does thin CA shrink when curing? |
Parser wrote: the thin stuff sucks right into pores really easily..why are you concerned about shrinkage? It'll do better than that. If it's sitting on a vacuum fixture, the glue will suck right through a piece of 1/8" rosewood to the other side. If I forget to turn off the vac before I wick in the glue on an inlay it starts with a puzzled look at why it's taking so much glue, followed by a sticky situation. |
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| Author: | Sheldon Dingwall [ Mon Mar 31, 2008 10:30 am ] |
| Post subject: | Re: What percentage does thin CA shrink when curing? |
Parser wrote: the thin stuff sucks right into pores really easily..why are you concerned about shrinkage? I'm in inlay mode these days. If I use CA to glue in a piece, there always seems to be some unfilled gaps around the part when I level it out. This is after two floodings of CA left slightly proud. |
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| Author: | Guest [ Mon Mar 31, 2008 11:34 am ] |
| Post subject: | Re: What percentage does thin CA shrink when curing? |
I always use the thicker formulations (with wood dust) because of this...why do you prefer the thin stuff? -Parser |
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| Author: | Erik Hauri [ Mon Mar 31, 2008 12:09 pm ] |
| Post subject: | Re: What percentage does thin CA shrink when curing? |
The thin stuff I use (Zap-A-Gap) shrinks about 50-60%. Pretty typical of hardware store-brand CA. |
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| Author: | Sheldon Dingwall [ Mon Mar 31, 2008 1:14 pm ] |
| Post subject: | Re: What percentage does thin CA shrink when curing? |
Guest wrote: I always use the thicker formulations (with wood dust) because of this...why do you prefer the thin stuff? -Parser We use medium so infrequently in our shop, every time I go to use it, the tip is either plugged or the CA's gone bad. |
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| Author: | clavin [ Mon Mar 31, 2008 2:12 pm ] |
| Post subject: | The thin CA |
The thinnest CA is great for relatively small-ish ( 2-4 inches around) inlays for headstocks and almost anything you can put on a typical fingerboard. It wicks underneath very fast and therefore lets you put the inlay in place, clamp it, then add the glue to the edges where it runs underneath. This works especially well on thinner inlays where the edges are very clear and still on the board, like on vines, etc.. For larger inlays and inlays spanning across the full radius of the board I have started to put clear (not black- I have not found a black epoxy or a black tint yet that doesn't seem to effect the hardness in some way- not officially tested- just an small observation) epoxy under in the middle to remove any air pockets (something that definitely does happen when trying to add thin CA to a much larger inlay- you can see large bubbles for with some corians and arcylics) and let that dry then go around the border ( say 1/2 inch from the edge of the epoxy to the route) with the thin CA to wick under the rest. Adding the CA too fast can smoke it out from the two reacting. That makes for a big mess. You have to wait until the epoxy has fully cured before adding CA. I haven't found an epoxy that does not bubble yet or show as clean as the CA. I was adding india ink to epoxy for a while but the bubbles needed filling with CA anyway since epoxy once dry doesn't re-bond, so I went back. The Star bond CA seems to have the fastest dry time and least bubbles. Craig L |
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| Author: | clavin [ Mon Mar 31, 2008 2:18 pm ] |
| Post subject: | Re: What percentage does thin CA shrink when curing? |
Quote: I'm in inlay mode these days. If I use CA to glue in a piece, there always seems to be some unfilled gaps around the part when I level it out. This is after two floodings of CA left slightly proud. This is called cheap CA. I was having the same problem. It was shrinking out under the dry areas giving a sense of it working, then you level it and it needs more gluing. Sometimes more than two or three times or more. Star Bond will fix that. The inlay edges may need a slight coating of glue after it's leveled, but I have not had to go back in after that and start adding like I used to before. It's great stuff. CL |
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| Author: | Michael Dale Payne [ Mon Mar 31, 2008 2:34 pm ] |
| Post subject: | Re: What percentage does thin CA shrink when curing? |
Sheldon Dingwall wrote: Guest wrote: I always use the thicker formulations (with wood dust) because of this...why do you prefer the thin stuff? -Parser We use medium so infrequently in our shop, every time I go to use it, the tip is either plugged or the CA's gone bad. Clean your tip with a little acetone after each use, keep the CA in the ice box when not in use and it will last for 4-6 months and longer. On another note thought I would mention that I dropped a small drop of thin CA on a piece of glass and allowed it to cure them measured the height of the B-B at .039” on Friday a week ago and measured again last night and measured .037” I will continue measure once a week till I get real board. But I suspect that the rapid shrink back everyone sees is absorption not really shrink back. When you pile a bunch of Thin CA in a channel like over filling an inlay you have to keep in mind that even the thin stuff does have a surface tension and may not fill all the available voids before it starts setting on the surface. And that it is still fluid under the surface and will flow as it can till it cures through out. I suspect this is the cause of the majority of shrink back most people experience. Now grocery store super glue I have no idea how it behaves as I have never used any except to glue a handle on a coffee cup. But I suspect it probably does not fare well as compared to Starbond |
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| Author: | Sheldon Dingwall [ Tue Apr 01, 2008 10:52 am ] |
| Post subject: | Re: What percentage does thin CA shrink when curing? |
Thanks for the tips. I'm going to source out some Starbond to give it a try. |
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