Epoxy brand question...

General Discussion
1

Hey, as mentioned in another thread, doing a fin repair which is my first EPS repair. The sources of resins here (Victoria, British Columbia, Canada) are limited, basically to one place that I know of. Industrial Plastics and Paints carries three lines of epoxy resin:

(http://www.ippnet.com/EN/main/products/FIBREGLASS/4506.html is the page that shows this product information)

System Three

Industrial Formulators

West System

These all seem to be Marine grade epoxy resins… I’m just not sure what would be the best to use for a surf application, if any. My only other option is to try to buy some resin from one of the local shaper/repair shops, but I haven’t been able to get through to them as they have random hours… So if none of these seems like good options then I’ll just keep trying to get to them. The folks at the shop are very unhelpful and all they know (or are willing to divulge) is that they carry a ‘surf resin’ which is what I should use for everything surf related. This is just a finishing polyester resin, so of no help to me in this case. Their wisdom having been tapped out, I turn to Swaylocks.

Anyone with any experience or insight into these resins?

2

I heard some good things about west system. I would use that one.

Get one of their filling resins (doesn’t heat up) I would choose the 407 (light strong and easy to sand).

3

Awesome, thanks for the input! …when I was a kid my dad always used West to build dinghies and other small boats. Feel at home with those tins of rectangular blue and white.

4

I never used West systems! I don’t really know the exotherm shit. Ask it in the shop too!

Choose the good hardener for this job.

I’m trying to find west systems is my area for its UV sability but I can’t seem to find it here.

I believe you have to use the slowest hardener for filling.

read this: http://www.westsystem.com/ss/epoxy-chemistry/

5

I’m not a fan of the West Epoxy system. When I worked for Knight and Carver Marine Construction in San Diego we used it. That was more than 30 years ago and their product may have changed.

I’ve been using a much better epoxy from AeroMarine. It’s cheaper, clearer, and much easier to work with. It’s the only epoxy I’d use. They mail it directly to me, so check them out at www.jgreer.com

6

nice, thanks for the reference! …it’s a bit on the cool side here, even in my shop so I’ll talk to the people in the shop about which hardener… they know absolutely nothing as far as it’s relationship to surfboard construction goes, but they should be able to tell me which catalyst is right …

7

sorry to correct you, but a hardener is not a catalyst. A catalyst is something that fastens a reaction but isn’t a part of the end product (it comes out again). It’s a common misconception, but nothing imortant. Just to let you know.

Polyester uses a catalyst (it’s a catalytic reaction). Epoxy uses a hardener (it’s a polyaddition).

8

Hey hans; No apology needed… I’d wondered about that, as I noticed that the different resin companies did refer to them as ‘hardeners’ for epoxy systems as opposed to ‘catalysts’ for polyester; so i suspected there might be a chemical difference. Thanks for clearing it up! So catalyst is evaporated or broken down during the process but hardener unifies with the resin during the process. More or less.

Thanks again for the clarification; Hope to get some work done on my fin plugs tonight, maybe install the sidebite plugs on my longboard and hopefully get all the prep done for the EPS fish repair. Psyched to get these boards back to water-worthy condition!

9

Jep that’s right, the catalyst evaporates. The catalyst fastens the reaction, so if you add more the reaction will be quicker.

With epoxy you have to add the right amount of A and B or the reaction won’t be complete.

poyester is: A+C -> B+C (the more C the faster, you can see C as a guy that links the others to eachother, more guys do a quicker job)

epoxy: A+B -> C

10

I do alot of work on boats and my boat is made with west system. good epoxy but I would just call stephen aftanas in tofino he will sell you some RR.

11

Hey BC.

Girvin probably has your best Canadian, west coast option.

West 105 based epoxy is primarily a boat epoxy which works great for sealing wood or as a glue… It’s a little amber in color and somewhat too thick for vacuum bagging, while not impossible though…

That’s all we used in the 80’s and 90’s… It’s cheap, strong and well made, just not thin or clear enough for my applications…

They also make a low viscosity laminating resin “Pro-set” which is clearer and much thinner and suitable for vac bagging, although more expensive than the 105 based resin…

System three is good stuff, relatively cheap, a littly higher in viscosity, but decent stuff…

I live 30km. outside of Toronto Ont. and I use MGS epoxy systems… its aerospace strong, very low viscosity and water clear in color…

Because it’s meant for airplane construction, I only use it on the outside, glass laminations because this epoxy is a little stiffer due to it’s over all strength…

I use Aeropoxy for the internal composite skin attachement… It’s also low viscostity, quite flexible, but quite yellow (amber in color)…

I’ve never tried R.R., but it’s what most of the surfboard builders use here so I’;d give that a try , especially if you can get it in Tofino…

I buy my epoxy in Toronto at : http://www.compositescanada.com/

Try to choose a thinner (low viscosity) epoxy that is as clear as possible ( for glass lamination),

Other than that,they’re chemically very similar…

Cheers Kiterider…:slight_smile:

12

Thanks kiterider and girvin!

I ended up getting the system three; it worked pretty well and was mellow to work with. Kiterider, I can see your point concerning it’s viscosity; it’s thicker than I’d expected. …the guy at IPP told me he wouldn’t recommend thinning epoxy; is there stuff to thin epoxy resins with that won’t interfere with the hardening, or…? …not a huge issue, but it would be nice to be able to cut down on sanding and get a thinner coat on with less work. I’m going to put the patches around the fin plugs tonight I think… the plug repair is looking solid and complete.

13

BC.

I re-read one of your later posts here, where you mentioned you were going to glue in your side bite boxplugs…

For inserts, boxes, etc., it’s advisable to buy a separate can of SLOW hardener, for use with inserts, as this hardener reduces the emount of exotherm (over heating) of the resin in a confined space such as a box insert…

This becomes critical the lower the eps weight, as resin "going -off will melt the foam core to shit, especially if the hole rout is sloppy and oversized and you have to use extra resin…

I have a seperate slow cure hardener I use for inserts, as well as complicated vacuum bag constructions where more working time is needed… I can also mix it with the fast hardener to get custom laminate working times…

I use core-cell inserts for my fin box and footstrap inserts, core-cell can take more heating…

You don’t have to buy a slow hardener, but keeping the plug hole tight helps a lot, as does higher density eps…

Cheers Tony…:wink:

P.S. In responce to your comments else where on this forum, and after following this group for the last 3 years; I stand by my observations, That dude’s an egocentric “tune”…

Nice one minute, mean the next…:frowning:

.End of story…

14

Hey BC,

Yes there are thinning solvents that work ok for epoxy…

I’ve used 99.9% isopropyl alcohol for thinning resin when dyeing/sealing balsa skins.

Not a good idea for laminating resin though, as it seems to leave the dried epoxy in a more “brittle” state…(just my personal observations).

Kinda’ like sucking the oils out of your skin, you’ll know what I’m talking about if you’ve ever had acetone on your bare skin… We used to wipe off resin on our hands with the stuff!! Duh!!!. We didn’t know any better…:frowning:

I only use isopropyl alcohol to clean my scissors and tools now ( out doors), and always wear gloves…

Xylene (sp) is supposed to work good thinning epoxy, but I’ve never tried it…

I don’t thickly “hot coat” my finished boards . After vacuum bagging, I apply a very thin coat of resin to seal any pin holes then sand smooth.

If you want to thin epoxy resin, the best way is to buy a slow hardener, which is much more “watery” than a standard hardener…

Warming up the resin and hardener, especially in the winter, allows for a thinner top coat, but be carefull, it can “kick” faster due to the added heat…

. My gloss/clear coats are sprayed on 2 part polyurethanes… A somewhat expensive and posionous chemical, but much lighter and less sanding.to get a gloss finish…

Gotta go glue on some rail bands,

Cheers Kiterider…:slight_smile:

15

Nice, thanks for the tech tips kiterider; I’d read that Xylene might work, maybe I’ll make some test batches with a few of those things and see what works the best. Right now all I’ve got handy is acetone to clean, but good to know that iso alc will work too! …way less gross. I have done some screenprinting and heard stories from a guy who has screenprinted for years at a few universities in canada about an old studio they had where after printing they would dunk their arms in a big bucket of acetone to scrub off the inks. Gross.

16

Acetone still has it’s place in epoxy construction…

I wipe the board down with it before additional epoxy applications or just before applying epoxy polyurethanes…

It cleans, degreases, and slightly soften’s the outer most laminate skin , preparing the surface for epoxy paints, clear coats or additional sanding layers of resin…

I no longer use it for anything other than the above, as the much cheaper, safer , 99.9% iso. alcohol does everything else , and some of the above, nearly as well…

Cheers Kiterider…:slight_smile:

17

Most of the boat epoxy’s are going to give you exotherm issues. RR slow won’t, especially in BC. Also no yellowing or breakdown under UV. Less vapor, less blush … easier to sand, better clarity, etc. Order that through fiberglasssupply.com. There in WA right across the border. Try it and you’ll see the difference.

18

Thanks greg! I was just checking out fiberglasssupply’s website; referred there by the Probox guys as possibly the cheapest place to order some from in canada.

I’m planning to shape some eps boards this summer; I will definitely get RR one way or the other for them. For this repair the System Three seemed to work pretty well, although it was surprisingly thick compared to polyester resin I’ve used, so it took some more work than I am used to to clear out the edges. Interesting working with epoxy vs polyester; I’d never realized how much difference there is. I imagine it being much more of a hassle for trimming cutlaps etc with epoxy as it seems harder to find that perfect point of cuttable softness + enough hardness to stay in place. I’m sure that’s just gettting used to it though.

19

Many jobs you do with epoxy are easier than polyester. We have a video which does explain many things. surfingvideos.com has that. Things like trimming laps are actually easier because you can trim earlier than with polyester because the resin sticks to the other side better. Means I can pull up the lap sooner without pulling up the lap … if you know what I mean. There’s no gel time , huge advantage. Less fumes, no solvents, no masks, easier clean up, easier wet out. I laminated for a long time with polyester , I can’t imagine ever doing that again. I’ve lost enough brain cells.