hey gr8…
the pic below illustrates that not all epoxies are equal …
and some like gregs are way out in front of polyester when it comes to yellowing …
took this photo today of a board in for repair …
i built this board in 2001 , its a fraction over 4 years …
about 2 years back , the customer asked me to grind out the fins and put boxes in …when i refinished the tail area i used epoxy instead of my regular silmar based polyester gloss resin …
so originally the whole board was finished in polyester over epoxy , then where the boxes were installed had an extra coat of epoxy over that again …
the difference was the UV filter in the new epoxy …
the rest of the board continued to yellow at the normal rate , but the area that had the UV stable epoxy has stayed the same in the last 2 years …
you can clearly see where the polyester is , then where the epoxy starts , its not a hard line because of the blend on the gloss …
so what goes yellower , polyester or epoxy???
the answer is neither , its the blank underneath which actually yellows (or in this case wood ) but the quality of the resin will determine how much damaging UV light actually penetrates through the resin to the board underneath …
i saw a board of gregs recently when i was over there , it was 5 years old and was whiter than a new polyester board …
i also saw some of gregs resin at airframes factory sitting 3" deep , set in a container …
it was clearer than water …
greg assures me ,even tho i havent tried it yet that his resins are UV stable , the evidence i saw makes that believable …
plus i know the difference from the variety of different resins ive used down here , that not all epoxies are the same …
just like rio mentioned not all polyesters are the same …
polyester resin sucks , its dark blue , has way to much solvent , cant filler with it without getting reactions and separations , then when it dries it goes a disgusting brown …
see what i mean , i just described general purpose p/e resin …
also the variety of epoxies reflects in all the different data sheets …
there is a way bigger difference in the nature of epoxies than there is in polyesters …
its just to broad to say epoxy doesnt get results …
which epoxy??
what brand ??
you have so much variety to chose from , you can dial in the exact characteristics your chasing , that is if you know what your looking for …
theres my point , all people have to work with is the failed attempts of others or cheap moulded imports , no wonder it gets a bad name …
and like greg alluded to , epoxy is the only road to techniques that will deliver the lightest strongest boards imaginable …
polyester is basically , entry level and retro , thats about the only decent thing you can make with it …
but for the ferrari , high performance aspects , epoxy is way out in front …
so rios comment about epoxy for kooks , well thats kinda funny …
i agree with greg , not only proof read your post , but also do some reading before you post , because youve walked into an audience of which most are quite well informed …
so im probably not the only person who has formed an opinion about your level of expertise in regards to the differences between the resins …
o and before you start talking about ride or performance , why doesnt everyone ride the moulded epoxy imports , and how everyone reckons there not high performance , but kooks boards as youve already stated …
a pig made from epoxy is still a pig …
just like a pig made from polyester is still a pig …
dont blame the resin blame the designer …
id still love to hear all the pitfalls of epoxy to …
maybe we can clear them up one by one …
my whole production consists of epoxy boards , to the point where some of my recent staff have never handled polyester …
a few months back one of the groms , mixed up some polyester resin for a gloss on a repair , afterwards he asked if he could go home coz he felt sick , he said the resin fumes made him feel ill …
not like the old days hey rio , tub of resin in one hand , beer in the other , an afterwork spliff behind the ear , while your toking your afternoon one , just soaking up all those brain killing solvents with a little substance to dilute the effects …
interested to hear your thoughts …
regards
BERT
1,2 …