Thread: Again!

OK. What am I doing wrong this time?
Both surfaces were scratched up well.
I cleaned all the materials before glueing (rubbing alcohol, 2x's), set to dry.
The T-88 Glue was mixed well, sat for 5 min, applied, sat for 1-2 min, clamped tight for 48hrs.

While sanding...they split!

WTF is the deal?!

C utz

Chris,

You may be clamping too tight. Epoxy has no strength when it is too thin, it needs a bit of body for strength. If you clamp too tight you actually squeeze the epoxy out from between the materials and it will be very weak at that point.

Also, the grit size for sanding may make a difference, if it is too fine then the scratch marks are not deep enough. Try using 120 or rougher and don't sand in one direction. Try to use circular motions to create more random scratch marks.

The screw-ups are part of the learning experience which does not end, at least for me it has not ended yet.

I'm glad I came across this post before I came to this stage with my first set. Thank you Chris for pointing out the possible issue and Vlad for providing the solution

Did you clean everything (I would use rubbing alcohol) prior to applying?
That can make a huge difference.

Also, sand blasting the metal (if possible) is superior to sanding.
You can actually get some very small very cheap micro sand blasters if you have a compressor already.

This link is to an airbrush set up for sand blasting.
http://www.dickblick.com/zz250/06/
There are some epoxies used to mount microelectronic dies that are formulated for minimal bondline thickness.

Rick

Harbor Freight has a tiny sand blaster for $15.

Not as fancy looking but cheap!

Thanks for the input guys!

I'm not sure if I clamped them too tight or not. I might have. I'm of the mind that 'tighter is better' and I know that's not necessarily true. So, it is a possibility. However, I only used those paper clamps to hold them together.

I do not own a compressor, so right now a sand blaster is not an option. The sand paper I used was 150 grit. Thinking that this might not be enough, I also scored up the surfaces with a drill bit (by hand, not with the drill).

I had cleaned the surfaces 2 times with rubbing alcohol.

All in all Friday was going pretty bad at the point in which the separation happened. Also, to make things worse, when taking the scales apart to fix them, while one side came completely separated, the other one cracked in half off of the other side. I think steam came out of my ears.

Being at this point, I did the cardinal sin....I used the gorilla glue. I know, I know I was being hastey, but now I'll know if this stuff is really not that good. At first inspection, while it did bubble out the sides a little (I expected this), it seems to be very solid. I will not know until I've worked with it a little to see if I made a big mistake or not. If the set falls apart, You'll see me post the results here...

NOW, today's job is to try and find some wood hardener!

Thanks again!!
C utz

You also may want to use acetone instead of alcohol. Someone mentioned that even alcohol could leave a bit of a film that will interfere with adhesion.

Originally Posted by FiReSTaRT

You also may want to use acetone instead of alcohol. Someone mentioned that even alcohol could leave a bit of a film that will interfere with adhesion.

Since it was the plastic liner, I did not want to use the acetone. Acetone degrades a good number of polymer/plastics. Plus, being too lazy to look up which plastic the liner is made up of, I just decided to use the ol' rubbing alcohol.

All in all, it seems as though the gorilla glue is doing just fine. I used a razor to cut off the excess glue that 'grew' from the sides, and finished the rest of the coarse sanding this morning (the sanding which resulted in the original split). The liners held up fine. I continued on hand-sanding the scales up to 600 grit, and then applied some water (I'll continue with 600 grit when they dry, and repeat with the water).

I'm trying to replicate those horn scales that I blew up in the microwave. I have the shape down, but am in the process of making them close to as thin as the horn one's were.

One thing I did notice was, when I added the water to the scales, they darkended as if they had been treated (this is where I can see what they might look like at the end when treated with trueoil). I have to say they look 'ok'. They are the walnut scales, and they look nice and all, but honestly a little boring. I think I have to add something, and have not decided on 'what' that something will be just yet.

Also, while the wood is being sanded smoother and thinner, I'm not too sure that it will need 'hardener'. I'm going to look around for some today, but if I can not come up with it, I'm just going to keep going ahead with working on them 'as is. Since they are glued to a brass liner, I do no think that they run much of a risk of splitting (famous last words....).

We'll see.

C utz