Replies to Resin selection - minimal discoloration

Replies to Resin selection - minimal discoloration

Sean Saunders

8/13/2014

Posted below are the replies that I received to my question about resins
that do not discolor as much. I posted this because the resin we have
traditionally been using changes colors to a point that I am not satisfied
with. If using a caucasian type pigment the appearance a few weeks later
is kind of a jaundice yellow and if doing an unpigmented socket it turns a
greenish hue.

What is proving to be just as difficult as finding a new resin is
convincing the technicians to try and accept a new material that does not
behave like what has been used for years....

Thank you to everyone who replied!
Sean Saunders, CPO



If by discolor you are including fading, none of the resins that I have
ever used will avoid that, as all are somewhat UV sensitive. The epoxy
resins seem less UV sensitive than non-epoxy acrylic resins, and the
flexible resins seem to be the worst. The IPOS resins, including
Carbonacryl, will yellow somewhat over time whether or not they is exposed
to the sun, but it will get worse if it is. Either of the Acsys Epoxy
Acrylic resins are probably the best ones I have found for this, but do
not discolor is not accurate, just discolor somewhat less than others I
have found.

At different times I have tried various resins not typically used in our
field, with similar results.

I don't seem to have this problem with Otto Bock Carbonacryl. I tried a new
Epoxy that seems strong but does not take pigments as well. Carbon shows
through.

I have used ER Resin. Available from PRS in Florida. SPS drop ships it.

I use it on carbon finish sockets and it doesn't seem to yellow. The resin
is much more clear colored to begin with. This is a 2 part epoxy and can be
a little tricky to work with. Best in a temperature control environment.
Slow to set when cold too quick when it is hot.

When I was first getting into the industry I interned with a fellow that
used boat resin from West I believe. It looked very nice and was very uv
resistant. The down side was 4-8 cure time I think. He would lam at the end
of the day and grind the next


In chasing the same thing, I have recently used some of the Otto Bock
Carbon Fibre Technique Acrylic Resin (don't have the code to hand) for some
of my novelty laminations, which is very transparent as well as very thin
(low viscosity) and to this stage (6 months in 3-4 sockets) it seems to be
holding up well color wise.

I'd be interested to see other replies you get.



We continue to use carbon acryl resin from Bock as we have had
discoloration issues with some of the AME resins, especially with our high
altitude sun. My technicians and I were just discussing these issues today,
and we would love to hear all of your responses


All you need is a UV light absorber additive


I just started to work abroad. Many places use the Orthocryl 80:20 by otto
bock they use the regular spt hardner with it I was told by them that it
is good for UE so since it doesn't change colors
It is slightly more elastic then the regular resin .


We had the same problem and found when we switched to OttoBock Resin we no
longer had the problem. It is more expensive but it will keep it from
turning yellow and makes the product more clear with a glossy look that we
really like.
Spend the money, it's worth it.


 I spent quite awhile discussing this very fact with our Chemist that
created our Epoxy resin. Every additive that you put into a formula, has a
desired effect, and an adverse effect. We've tested almost all of the
current resins available in the O & P industry and we have not found one
that is completely UV stable. It seems that the additives that could make
it stable play havoc with the working times, setting times, and alter the
chemical makeup enough that the end strength is lessened.
    Then we all add pigments to the mix, and very few pigments are UV
stable that are flesh colored. In a lot of cases, it's not the resin
changing dramatically, but the pigment used, or the hardening agent. It's
not just a resin issue is what we found out in our discussions.
    There are ways to make this happen, but it significantly adds to
manufacturing expense and in some cases, adds another layer to our sockets
to basically clear coat over a socket.
Long winded answer, but I hope this helps,


Something I've noticed, & u may know this already, but cigarette smoke will
fade the socket quicker than anything everytime.


All modified epoxies will discolor. Most epoxies will too for that
matter. Use the 80:20 resin from otto bock, but you have to degas it with
a desiccator. Extra work but that’s what we do and it is worth it since it
is a superior product.


I've been asking techs this for yrs. One swore adding armorall to the resin
 did it...not. All whites in t-shirt laminations yellow.