Here's a Question from Volume 3 - Issue #3 issue of RodMaker magazine:
I have been having problems with my thread wraps becoming
very blotchy and uneven colored when I apply epoxy rod finish.
I am using color preserver, and always thin it about 50/50 with
water and then 2 coats. I use the U-40 LS2000 rod finish and
like it except for the blotches that appear on the thread when
it goes on. Would different finish correct this problem? Do
I need to switch to a different thread brand? What about not
using any color preserver? I like to preserve the bright color
of the thread, but will stop using it if it is causing the blotches.
~ Matt, Brooklyn, NY
One of the main purposes of color preserver is to seal the thread
against penetration by the eventual epoxy finish. If epoxy or
urethan wrap finish penetrates the threads, they will darken,
becoming almost translucent. The problem you are having, is not
with the epoxy finish, but rather with your color preserver or
the method you use with it.
If the color preserver properly penetrates and seals the threads, the
epoxy finish will not penetrate those same threads and thus they
will not darken, either overall or in spots. In your case, the
color preserver is not fully sealing the thread and preventing
the epoxy from getting in there. Wherever the epoxy penetrates
the threads, you wind up with a dark area. Where it is prevented
from penetrating, the thread keeps its bright color. Hence the
blotchiness you speak of.
There are a couple of things to look at here. You did not specify
the type of color preserver you are using. I will assume it is
a water base acrylic type (most are). By thinning it so heavily
you are, in effect, pretty much just applying water to your thread.
The water evaporates, and the solids in the color preserver were
not there in sufficient amount to completely seal the thread.
The epoxy then penetrates in some spots and you get dark areas.
I do not know if the instructions that came with your particular
color preserver stated that you needed to thin it. I do know that
I rarely thin my color preserver, unless it has started to thicken
in the bottle and needs to be restored to its original consistency.
Another possibility is that your application is not thorough enough
to fully penetrate and seal the thread completely through to the
blank. Remember that your expoxy will seep in around the edges and
along inside the tunnel formed between the thread and guide foot.
If it is able to penetrate the thread from underneath, it will
darken just as if it had penetrated from outside of the thread.
My suggestion is twofold: Don't thin your color preserver any more
than about 20% and not at all if it is thin enough to work easily
and quickly penetrate the thread. Next, you should apply a full
wet coat to the threads, making sure they turn uniformly dark.
Allow it to penetrate a few minutes and then remove any excess.
Work some in alongside the guide foot tunnel. Let it dry
overnight, allowing for environmental difference, before applying
the epoxy. You should be able to get nice results following this
I will also add that alcohol based color preservers tend to dry
faster than water based ones. Remember that alcohol is more
volatile than water and evaporates faster. With these color
preserves you will have to work a bit quicker when applying and
working it into the threads. You will not be able to go back 10
minutes later and remove the excess, if there is any, or you will
disturb the surface of the preserver which has already set.
~ Tom Kirkman
If you have any tips or techniques, send them
along! Help out your fellow rodmakers!
~ Publisher, FAOL