Hi all. I was in the middle of repairing a tip section, replacing some guides because of saltwater corrosion... and as I was heating the epoxy up to cut into the thread wraps the blank literally folded in my hand. The break was underneath the thread wrap. My initial intention was to clean the section up and insert a dowel with another broken tip section I had... no big deal, right? Except there was another break in the tip section, again as I was doing the exact same thing... heating the epoxy up and the blank folded. Here are some quick facts. I couldn't have held the blank section under heat for longer than 4 seconds - I counted the number of seconds as my methodology for heating epoxy up is the exact same for any guide wrap. Next, I only cut on the guide foot, parallel - but the break was perpendicular, eliminating my thought that I may have cut into the actual blank.

Has anyone else had this happen? Am I insane to think 4 seconds under heat isn't too long? Should I just chalk this up to poorly made graphite blank?

4 seconds could very well been too long, if the heat was high !\\, like from a flame ! A flame near a blank or rod is a prescription for disaster !! If for some reason you feel you must heat it, use a hair dryer or low heat heat gun.



Edited 1 time(s). Last edit at 10/10/2022 12:13PM by Phil Erickson.

That's totally fair. Just unexpected... I haven't had any issues on any other tip sections. My heat may have been high, I generally keep rotating the blank when i'm heating it up, but i'll have to do some more R&D.

Thanks

Too much heat can certainly cause a tip section to fold over. I’ve done it before! A heat gun, or even worse a flame, just gets too hot, and I don’t use them any more. If you want to soften the epoxy, use a hair dryer. A Hair dryer, unlike a heat gun, won’t catch your hair on fire, so it is much safer to use without affecting your blank.
Norm

Why would you heat the epoxy? It's simply not necessary nor advised.

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I agree with Tom. I believe that the value of heat in the entire rodbuilding craft is highly misunderstood. Not just in the process of removing guides.

If you get the blank hot enough, the resin that locks the graphite fibers into place will soften, and the result is exactly as you describe, the blank folds in your hands. When blanks are made, the fibers are held in place by the pressure between the mandrel and the cellophane tape wound around the blank. They are then cured at temps of around 300 F give or take 50 degrees or so (based on what I've read over the years). If you get the blank back up to those temperatures, the resin will melt again. A few seconds of heat with the source moving side to side while the blank is turning may be fine in some areas of a blank, but could cross the line in others. Unfortunately, the resin doesn't soften slowly to allow you to feel the failure coming on. It happens all at once, and then it is game over.

As nice as it is to be able to slice through softened finish epoxy, the risk is not always worth the reward. Slice through the epoxy and thread on top of the guide foot and then the wrap should peel off. If the guide is going back in the same place, clean up what will clean up without heat. Any bits of leftover epoxy will blend in when coated with a fresh coat of finish. If the guide is being moved, then the work becomes harder to remove the excess epoxy and get the surface of the blank to appear uniform.

Joe, since the resin is not a thermoplastic, but is a resin made from a chemical reaction, and doesn't have a "melting point" like a thermoplastic, is it not true that the high temperature degrades/destroys the material instead of calling it "melting?"

If it were truly just melting then after it cooled it would have almost its original integrity, like a true thermoplastic, and the blank resin does not have anything near its original integrity after heating that hot.

??

Very good advice in your last paragraph, in my opinion.

A razor blade across the top of the guide foot removes the epoxy and thread slick as can be, I never have seen the need for heat. Epoxy is not tough and hard like Permagloss when removing guides and heat would have zero effect on Permagloss.

Mick,

Fair enough. I should have put melt in quotes or used a little more descriptive language because as you said, it isn't the same as melting.

Thanks, Joe.