Thank you for the kind words. Means a lot coming from you. Your post that I replied to indicates that you aren't the target audience of my initial post, however. It is nice to see that you can notice and appreciate what I was intending, though. So thank you.
cue vibration
- Thread starter cueassembler
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Thank you for the kind words. Means a lot coming from you. Your post that I replied to indicates that you aren't the target audience of my initial post, however. It is nice to see that you can notice and appreciate what I was intending, though. So thank you.cueassembler
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Well, I redid the joint pin and the buzz is still there. No surprise, but worth a try. I may finish it and shoot with it before fixing it. I am curious if it will get worse.
Is a glue relief channel a good idea for this joint with thick epoxy?
I sure appreciate the all the responses from the experienced builders in this thread. I will be giving a lot more thought to this process.
Leonard Mitchell
Is a glue relief channel a good idea for this joint with thick epoxy?
I sure appreciate the all the responses from the experienced builders in this thread. I will be giving a lot more thought to this process.
Leonard Mitchell
The idea is to release pressure, the thicker the epoxy the worst it is, end result is you ruin the wood threads.
Mario
Yes a glue relief is a good idea. The glue relief allows for the epoxy to be forced into every nook & cranny of the joint, and for any excess to escape so you do not create a compressed air bubble. That compression causes outward pressure on the wood just like air in a tire, and it will blow out if significant enough. Same can happen even if there's no air, just fluid, except that the fluid pressure busts the wood much sooner. Either way, you end up with failure. If by some chance you get the joint faces together with an air bubble trapped inside, the pressure will alleviate soon enough but you'll be left with an area of void space inside the joint. Any of these symptoms can be usual suspects in buzzing "A" joints, and all of them are prevented by having a glue relief.
Why would thick viscosity be bad?
What are thin epoxies good for? Soaking into the fibers before curing, thus leaving a joint deprived of glue?
The thicker epoxies stay put. They still tack & adhere well to the wood, but do so without having to saturate the wood. In a joint with only a few thou void space between the tenon and bore wall, those components are near certain to rub as the cue vibrates & flexes. An epoxy that soaks away into the wood, leaving that space empty, will result in buzzing. It may not be every cue. It may not even be one in 20 cues. But how many does it take to realize something is going on?
T88 is an outstanding epoxy. Good manufacturer, solid product, time tested, and thicker than ketchup. Why would T88 be a bad choice for "A" joints?
My preference is to start with a thinner, slow set epoxy. Then I can pre-glue the parts and give it time to soak in. If it starts looking dry it gets another coat. Then I can thicken the mix to suit the application if needed and put the pieces together.
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Thank you, Murray, for describing your method.
If I had asked for somebody to describe a method that allows me to effectively use thin viscosity epoxy, then the above would be a solid answer. And Murray, thank you again for taking the time to explain. But it's not what I asked. I asked why it's a bad idea to use an epoxy thicker than ketchup.
I asked that because of several reasons. First of all, it was a statement made, but not substantiated. Second, West 206 is formulated specifically for the thin viscosity, for the purpose of wetting out & hardening sheets of woven fiberglass. Soaking is its designation, not structural bonding. That's not to say it can't be used effectively as a bonder. Indeed it can, but requires extra steps to be taken to insure sufficient bond strength. On the flip side, you have epoxies that are formulated specifically for structural bonding, and coincidentally require very thick, sticky consistency. An "A" joint is indeed a structural, permanent joint, so logic dictates that a structural bonding epoxy would be the chosen adhesive. The third reason I asked is because my own experience closely mirrors the idea that structural bonding epoxies tend to be a better choice than trying to get wet-out epoxies to do the same job. It's no stretch to believe that a structural bond epoxy is a good choice to use in a structural bond joint. My experiences tell me that I have had more joint failures with 206 than I have had with T88. Same joint, same guy doing the work, just different epoxy. So when I see a claim that it's a bad idea using epoxy thicker than ketchup, I naturally want to know why. Telling me it's bad doesn't mean anything. Tell me why it's bad.
Sorry if I am nit picking. I don't mean to be. I really am interested in this subject because it's something I have struggled with my entire time as a builder. I have changed my "A" joint configuration dozens of times, and rotated through seemingly dozens of epoxies, trying to find the best method. I forget things I used to know, often times on purpose because I was actually wrong. So forgive me if I am a little more involved in this topic and perhaps even a little annoying. I'm trying to learn.
Sorry if I came across as telling you your method was wrong. My intent was to just share what worked for me. When I have time to type it out I'll address the rest of your post.
No apologies, Murray. I didn't feel you were saying anything except that you had a preference. I appreciate your openness to discuss. Seriously.
No probs here.
The process was actually described by Royce ( Thank you Royce and we miss you already ) on how he uses west system epoxy for his cores and avoided that "dry spot" problems. He was reluctant in using poly glues as well.
It dawned on me then, to do the same for the A-joint.
I was using Hysol and 3M DP for A-joints then. Solid epoxies. Better numbers than T-88 iirc. The better epoxies have never been a 1 to 1 mix afaik . They have always been 2-1 or 4-1 or up.
When I read Royce's , I made some mock-ups and stuck them in the trunk of my car. Weeks later , the one with west 206 did not even show a hint of buzzing . Two other mock-ups did . One had a thin mix like you described. It buzzed within a week.
I also made some putties and left them on my lathe pan. The mustard thick 206 had to be hammered for it to give . And that was on a dirty pan.
206's adhesion strength is unquestionable . It's heat resistance is nuts . I used in on joint pins . I had to blow torch one screw one time . It would not give easily even when the SS screw was already full orange .
I've had zero failures from 206 after reading Royce's post years ago.
http://www.westsystem.com/ss/basic-bonding-techniques/
That is the golden spoon video.
Peeps should all thank MT.
Some have kept this a secret for a while now.
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I have successfully used both on "A" joints. Both are plenty strong. I never liked the 206 as much because of the extra time & extra steps involved. I never like T88 because it's such a PIA to get out of the bottle for mixing lol
Aloha
Great read so far, But there is one issue that has not been touched in this thread that I believe is very important.
Depending on the type of woods being used, be sure to prep the surfaces for the glue properly. A lot of the woods will have natural oils in the fibers which can keep the glue from bonding. Cleaning with an acetone, and blowing out all the chips is a good habit to create to keep the threat of a buzz to a minimum.
Good to see you posting again Eric, it's been too long.
Aloha
Great read so far, But there is one issue that has not been touched in this thread that I believe is very important.
Depending on the type of woods being used, be sure to prep the surfaces for the glue properly. A lot of the woods will have natural oils in the fibers which can keep the glue from bonding. Cleaning with an acetone, and blowing out all the chips is a good habit to create to keep the threat of a buzz to a minimum.
Good to see you posting again Eric, it's been too long.
Aloha