I had a problem with bubbles forming in my epoxy. It was the first coat of the underwraps of a tiger wrap. I used CP - 1 coat. I first applied a relatively thin coat of epoxy (one that I've used before) with a brush and kind of 'pushed' it into the threads. I had burnished and pushed the threads in many different directions, so I figured that using a brush for a thin coat would push the epoxy into those more 'open' areas. After this thin coat, I used a credit card to lay it on thicker, which I have done in the past. (same batch of epoxy) In three diferent areas, one large bubble formed. I used a blow dryer to release them. 20 minutes later, bubbles are back and I repeat the dryer treatment. This happened 4 times until I decided that I'd cut them and fill them once dry. After opening, the bottom of the bubble showed the thread. The thread is emroidery thread that I've used before with no problem. I cant think of anything that could hold that much air. I guess I should have just applied a thin coat, let it dry, then come back with my thick coat as a second application.

Thanks guys
Steven

When you "pushed" the epoxy into the thread, you created thousands of tiny micro bubbles. The thicker application you made just after made it hard for all those little bubbles to rise and escape the epoxy.

Never brush or move the epoxy around - put it on as evenly and quickly as you can then let it flow and settle of its own accord - it knows how to do that.

Very large or insistent bubbles that keep coming back in the same spot can point to something on your thread that shouldn't be there.

............

OK, got it Tom.
barring thread contamination, would you say that I would be better of using one of the 'lite' formulas for my first coat (just laying it on) then come back with my normal hi-build to get the desired thickness?
Thanks, Steven

There is slight difference in the appearance of a bubble and a fisheye caused by silicone contamination in the form of lubricant on embrodery threads. If you are doing a Moiere one of the the bottom threads may have silicone and the other may not in the area causing a "fisheye" that is caused by the presence of silicone. Most tend to solve that problem with color preserver on top of the treated thread. All finishes will tend to "pull or move around" when silicone is present - If you are seeing this and trying to go back over an area to level it out it will only make the "brushing formed bubble" problem worse. If the problem is really bad consider CP first or find a thread that does not contain a lubricant.



Edited 1 time(s). Last edit at 10/03/2008 01:59PM by Bill Stevens.

Bill,
That is one thing that I wanted to ask, what does a fisheye look like?
(other than a fish's eye......)
Steven

What a "fish eye" due to silicone contamination in finish looks like - Apply finish to a area - leave it alone - it may look like it is laying flat and everything is OK - wait a few minutes - look back at the same area and you will see a small circular or streaky area that appears to have no finish - kinka like a dimple or a shallow crater - once they start forming it will be impossible to get the finish to lay nice and flat in that area. The best solution to this problem is to use thread specifically used for rodbuilding.



Edited 1 time(s). Last edit at 10/03/2008 03:59PM by Bill Stevens.

Lite? Maybe. I've never found it necessary but I would think that the Lite releases any introduced bubbles more easily. And there is certainly nothing wrong with topcoating the Lite stuff with the regular or Hi-Build.

...........

I think if I had that problem, I would add some micro glitter. The glitter wll break those tiny bubbles. An if there are still bubbles the glitter well hid them. Besides in the sun that little sparicle is cool.
Good Wraps Bob

It my limited experience, I have "created" fisheyes in my finishes and noticed that it occurred only when using TM lite. Heeding the words from the wise builders on this board, I resisted the urge to blame the epoxy (epoxy problems are user errors, not composition errors 99.9% of the time). I lightly flamed the finish and the eyes dissappeared. Thinking that was it; heat fixed the problem. It took a minute to dawn on me that when flaming the finish, some of the finish was releasing and dripping off. The long winded (sorry) set up for my proposed psuedo-hypothesis is that I think there may be a "critical mass" to the light finishes and when too much is applied, it separates as it cures creating pockets. I have not performed actual experiments, so this anecdotal. But since that epiphany, I have thinly applied the epoxy and have not seen the fisheyes with TM Lite. FWIW
Obed

I would use at least two wet coats of CP. It is thin and should soak into the thread too eliminate bubbles.

Posted by: Steven Loughery (---.trapac.com)
Date: October 03, 2008 09:21AM

Steven'spost was about bubblesnot fish eyes.

I had a problem with bubbles forming in my epoxy. It was the first coat of the underwraps of a tiger wrap. I used CP - 1 coat. I first applied a relatively thin coat of epoxy (one that I've used before) with a brush and kind of 'pushed' it into the threads. I had burnished and pushed the threads in many different directions, so I figured that using a brush for a thin coat would push the epoxy into those more 'open' areas. After this thin coat, I used a credit card to lay it on thicker, which I have done in the past. (same batch of epoxy) In three diferent areas, one large bubble formed. I used a blow dryer to release them. 20 minutes later, bubbles are back and I repeat the dryer treatment. This happened 4 times until I decided that I'd cut them and fill them once dry. After opening, the bottom of the bubble showed the thread. The thread is emroidery thread that I've used before with no problem. I cant think of anything that could hold that much air. I guess I should have just applied a thin coat, let it dry, then come back with my thick coat as a second application.

Thanks guys

In any case when using a sewing thread. I would definitely use at least 3 lite coats of CP. Let each coat throughly dry. Bubbles are caused by trapped air being released. Once the last coat of CP has throughly dried, then add a thin coat of finish, let that coat get tacky. Then add your next coat of finish, add additional coats if needed. As for a fisheye problem, this is generally caused by 3 items. #1 silicone which is added to most sewing threads, oily hands (wash your hands frequently if you have oily hands or some kind of oil on the blank, wash the blank before wrapping, #3 air born particles from spray cans or open wax containers. Keep these containers out and away from wrapping finishing areas. Air born particles can also contaminate the finishes also.
Good WrapsBob
Steven

Thanks Bob
That was going to be my approach, a few coats of CP, a light, thin coat of epoxy, and finally a normal coat to get the thickness i want.
Thanks everyone