Hi all
What would be the cause of tiny pitting/holes in the surface of my thread finish?
It's as though tiny bubbles have burst but the finish hasn't levelled

heat and rods don,t mix well...

Perhaps the two-part epoxy was whipped rather than blended. The bubbles did not come from inside the epoxy containers.

Almost surely they are micro-bubbles. These can be caused by mixing/stirring too vigorously or excess application of heat which tends to boil the finish and actually create such tiny bubbles.

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

Greg,
When mixing, mix slowly to avoid mixing in air.

If you use heat, which I use on every build, use gentle heat. Excess heat boils the finish and introduces bubbles and Mr. Kirkman indicated.

There is nothing wrong with using heat. The vast majority of the commercial rod shops use heat after finish application to slightly reduce the viscosity of the finish for more uniform and quicker leveling, but it is gentle or moderate heat to avoid the afore mentioned problem.

Take care

Greg, don,t play with fire especially starting out as a rod builder..use CP to seal your wraps then you won,t have any bubble problems and have to use heat to get them to bust or get the epoxy to soak into the wrap...it,s really so much simpler this way and looking at a guide wrap and seeing the guide foot is so uncool..lol.

Here is a video on measuring and mixing Flex Coat Finish:
[flexcoat.com]

Flex Coat Company
Professional Rod Building Supplies
www.flexcoat.com

Try gently blowing thru a soda straw on the wraps after coating. The CO2 in your breath helps bubbles to release. Don't spit on it. Actually after finish is mixed if there are some bubbles in it and there very likely will be, blow thru the straw right into the cup and you can see this miracle take place right before your eyes.

after mixing your epoxy let set 30 sec, then drop one or two drops of DNA on top of epoxy , watch what happen's
to the bubbles in the epoxy , don't mix after the DROPS just use , it works great for me , still a beginner learning

William Sidney
AK

Bill,
Really, please don't use DNA with finish epoxy.

DNA really is not compatible with finish epoxy and does not go into solution with the epoxy.

If you do need to put a couple of drops on the finish epoxy, rather - use either Acetone or Xylene. The preferred one to use is Xylene which is the industry wide solvent for epoxy.

Best wishes.

What Roger did not mention, is that if you either one, be sure you mix them into the epoxy!

Roger I don't under stand when I started, I was showed that if the epoxy had some bubbles on or in it, an you put one or two drops on the mixed epoxy , one will do all the bubbles go to the side an pop,
never tried acetone , the DNA. just caused a temp. change to the top of the mixture , I never did mix it in just applied it went on fine . just let the DNA. evaporate , what is the short coming's of using DNA.
as I use on epoxy ??? any input will be great Roger

William Sidney
AK

Bill,
If using chemicals, I like to insure that they are compatible and will not cause issues with each other or in combination.

Here is the test:

Just mix up a small batch of finish epoxy in a glass bottle and put in a small amount of alcohol and attempt to mix them together.

Then, repeat using finish epoxy and a small amount of acetone.

Then, repeat using finish epoxy and a small amount of xylene.

-----------------------------------------
From another source:
Xylene is used as a solvent for printing, rubber, and leather industries. It is a common component of ink, rubber, and adhesive. In thinning paints and varnishes, it can be substituted for toluene where slower drying is desired. Similarly it is a cleaning agent for steel, silicon wafers, and integrated circuits.

and:

Solvent. Acetone is a good solvent for many plastics and some synthetic fibers. It is used for thinning polyester resin, cleaning tools used with it, and dissolving two-part epoxies and superglue before they harden. ... Acetone is used as a solvent by the pharmaceutical industry and as a denaturant in denatured alcohol.

and :
Here is a very good article by West Systems Epoxy manufacturing about thinning epoxy adhesive and resin:

[www.epoxyworks.com]

thanks Roger..i used to wonder why commercial rods just about always in the rain the guide wraps would get very cloudy..now i know..they thin their finish epoxy to get more penetration of the thread and thinned epoxy has much less water resistance..it absorbs the water and turns cloudy..and thinning with heat does the same thing..good article..

Ben,
Actually, I have to slightly disagree with your statement. I don't actually know of any commercial rod builders that thin their epoxy finish and over the years, for the few commercial rods that I have used have never found an issue with a cloudy finish on the thread wraps.

But, maybe I have been lucky.

You can go out and do a search for tours of various commercial rod building factories and in none of the videos have I ever observed any finish being thinned. But, they may thin the finish but never film it.

Take care

Roger,
Thank you for the exceptionally informative and point-blank read as to why not to attempt to alter then chemical properties of any epoxy by thinning or heating. Everyone should take serious note of the context!!!

Mark Talmo
FISHING IS NOT AN ESCAPE FROM LIFE BUT RATHER A DEEPER IMMERSION INTO IT!!! BUILDING YOUR OWN SIMPLY ENHANCES THE EXPERIENCE.

Roger thanks for the INFO will take it an go . will stop using it as a mix , thanks again

William Sidney
AK



Edited 1 time(s). Last edit at 10/13/2019 12:18PM by Bill Sidney.

it,s interesting also that thinning affects the hardness of the final cure..the wraps are easier to get scuffed and scratched..

I have actually caused the micro bubbles during the application Process! High lathe speed, rough finish ( like carbon fiber), to much pressure at the brush = micro bubbles!???????????.
I recently started applying finish with a brush and using the small spatula to spread down the blank. Basically, I’m saying you can cause the micro bubbles during your application process! As Tom Kirkman states - get it on the blank, and leave it alone so it can do its thing!

Jon Hood

sounds a lot like micro-bubbles/pinholes (during mixing and even during application) that do not level out enough for epoxy to flow back. could also be contamination, but that usually forms craters/holidays.

Some people say DNA (denatured alcohol). That would reduce the surface tension of the epoxy + can help thin the top layer of epoxy to let the air bubbles travel up faster and pop. This could also compromise the overall end result of the coating's performance. Can definitely reduce hardness of cured epoxy.

Another technique used would involve heat/flame. Heat guns could blow the epoxy to areas that you don't want coated. A gentle flame (non-direct) from a clean burning source is another option. This quickly thins the epoxy and allows for trapped air to release. This also thins the epoxy to possibly flow in and level out any pinholes. be cautious as heat will accelerate epoxy cure time, and if you use a regular lighter it does not burn clean and can leave smoke/smut marks in the epoxy.