Epoxy system preferences?

   This must have been discussed before, but I can't find a thread on it both here and at www.boatdesign.net. So I thought I would ask:
Which epoxy (systems) do you guys prefer?
The background: I am starting on a "stitch and glue" build (a Farr 3.7) and looking around for a good solution. The two main options appear to be SP 106 and West 205 (with slow and fast hardeners depending on the exact task). In the past I have used SP 106 for GRP and carbon repair work and was happy with that. Of course reading the Gougeon Brother's book one is left with the impression that the boat will fall apart, you will develop boils on your hands and ultimately die if you don't use the West System  .

Any strong opinions? Alternative suggestions? Does it even matter?

Thanks for any comments, Chris

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ChrisB14 Send Private Message Find Member's Posts Visit Member's Homepage Posting king Joined: 29 Oct 13 Location: London Online Status: Offline Posts: 101	Post Options Post Reply Quote ChrisB14 Report Post Quote Reply Topic: Epoxy system preferences? Posted: 08 Apr 14 at 6:01pm
	This must have been discussed before, but I can't find a thread on it both here and at www.boatdesign.net. So I thought I would ask: Which epoxy (systems) do you guys prefer? The background: I am starting on a "stitch and glue" build (a Farr 3.7) and looking around for a good solution. The two main options appear to be SP 106 and West 205 (with slow and fast hardeners depending on the exact task). In the past I have used SP 106 for GRP and carbon repair work and was happy with that. Of course reading the Gougeon Brother's book one is left with the impression that the boat will fall apart, you will develop boils on your hands and ultimately die if you don't use the West System . Any strong opinions? Alternative suggestions? Does it even matter? Thanks for any comments, Chris
	B14 GBR 748 Bullet B In build: Farr 3.7 GBR 410 (both sail number and the current number of loose parts)

Rupert Send Private Message Find Member's Posts Really should get out more Joined: 11 Aug 04 Location: Whitefriars sc Online Status: Offline Posts: 8956	Post Options Post Reply Quote Rupert Report Post Quote Reply Posted: 08 Apr 14 at 6:57pm
	Ed Bremner on the cvrda site always suggests that speaking to Matrix Mouldings (www.matrix-composites.co.uk) is a good idea.
	Firefly 2324, Puffin 229, Minisail 3446 Mirror 70686

JimC Send Private Message Find Member's Posts Visit Member's Homepage Really should get out more Joined: 17 May 04 Location: United Kingdom Online Status: Offline Posts: 6660	Post Options Post Reply Quote JimC Report Post Quote Reply Posted: 08 Apr 14 at 7:10pm
	As I recall West is mix by weight and SP is mix by volume. That in itself is probably enough to give most people a preference for one or the other. And yes, there are others which have a good rep. Sicomin being the most obvious example. Frankly at our amateur level there probably isn't much to choose between Sp/Gurit, West and Sicomin products. I normally use SP because I like to mix by volume, but if I were local to Bristol I would be strongly tempted to use Matrix and Sicomin simply because Wiz at Sicomin has an ear that is well worth bending.

Oatsandbeans Send Private Message Find Member's Posts Far too distracted from work Joined: 19 Sep 05 Location: United Kingdom Online Status: Offline Posts: 382	Post Options Post Reply Quote Oatsandbeans Report Post Quote Reply Posted: 08 Apr 14 at 7:52pm
	SP106 and WEST 105 with their associated hardeners are now very similar. The SP 106 used to be a bit better in the extreme cold because when you mixed it, it generated a kick on mixing, that helped push the cure through, but they ditched that because it wasn't so good on colour so there is not much in it. Both systems are fine for wood epoxy and general repair work. The most important thing with these epoxy systems is getting the ratio right as they have low hardener addition rates which are sensitive to getting it right, and if you over, or under do, the hardener the properties are awful.

craiggo Send Private Message Find Member's Posts Really should get out more Joined: 01 Apr 04 Location: United Kingdom Online Status: Offline Posts: 1810	Post Options Post Reply Quote craiggo Report Post Quote Reply Posted: 08 Apr 14 at 8:27pm
	I've used West by volume and by weight with no difference in terms of the results. The biggest issue is always amine blush but if using it as an adhesive with low density filler this doesn't usually present a problem. If you do use West, I'd recommend using 207 hardener (for clear coating). Once you've cut all your panels out, roller it on all surfaces. The only bit of the West system I've been disappointed with is the filleting blend which used to give a nice orange wood colour but now seems a bit beige. In the Grad fleet they were quick to make use of West in the mid 80s and these have proven to be some of the most robust long lived competitive boats in the fleet. I have used Sicomin resins when we built the C-class Invictus, but this was exclusively with Carbon rather than wood!!!!! Found it to mix out well and cure consistently. Wiz is always full of good advice and will make sure you get the right stuff, but I found it a bit pricey. I've never used SP so can't comment on it.

I luv Wight Send Private Message Find Member's Posts Visit Member's Homepage Really should get out more Joined: 28 Jan 05 Location: United Kingdom Online Status: Offline Posts: 628	Post Options Post Reply Quote I luv Wight Report Post Quote Reply Posted: 08 Apr 14 at 10:18pm
	I like Sicomin SR8500 ( from Matrix ) for vaccing hulls and foils, and general purpose SP320 for bonding, filling and coating. I have tried many different other ones, but there's always seems to be some problem - crystallization, too sticky, too brittle with an overnight cure, too fast, too slow, too brown, too shrinky as a coating, goes off, doesn't like damp or cold, too sticky residue on the cured resin, too bendy when cured ( SP Speedipack!), too smelly. Measure with kitchen scales! Edited by I luv Wight - 08 Apr 14 at 10:20pm
	http://www.bloodaxeboats.co.uk Andy P foiling Int Moth GBR3467 Freedom 21 Codling

ChrisB14 Send Private Message Find Member's Posts Visit Member's Homepage Posting king Joined: 29 Oct 13 Location: London Online Status: Offline Posts: 101	Post Options Post Reply Quote ChrisB14 Report Post Quote Reply Posted: 09 Apr 14 at 4:04pm
	Lot's of very useful comments and advice, thanks! The brief response is that I guess I will be contacting Matrix for detailed advice and materials for our build. From what I can see West 105, SP 106 and Sicomin SR 5550 are all roughly the same price (if anything Sicomin a tad cheaper), with substantial variations depending on where you buy. SP 320 is a major step up in price, though. Andy: Is it simply that 320 is clearer than 106, or are there other benefits? Let me see if I got this right: a resin system requiring 3:1 is less sensitive to small measurements errors than a 5:1 system? I assume that's because for a given error the relative effect is smaller? It also appears that all three (Gurit, West, Sicomin) now specify both weight and volume ratios. I have found that people tend to hold deep convictions about which is the more reliable way to go. Off the top of my head, I would prefer volume (using syringes) for small amounts and weight for larger amounts. But maybe weight is the best way to go in any case. Thanks again! Chris
	B14 GBR 748 Bullet B In build: Farr 3.7 GBR 410 (both sail number and the current number of loose parts)

alstorer Send Private Message Find Member's Posts Really should get out more Joined: 02 Aug 07 Location: Cambridge Online Status: Offline Posts: 2899	Post Options Post Reply Quote alstorer Report Post Quote Reply Posted: 09 Apr 14 at 4:46pm
	which is more reliable is purely down to your measurement systems. Really clever formulation can be done that makes the two ratios the same...
	-_ Al

Oatsandbeans Send Private Message Find Member's Posts Far too distracted from work Joined: 19 Sep 05 Location: United Kingdom Online Status: Offline Posts: 382	Post Options Post Reply Quote Oatsandbeans Report Post Quote Reply Posted: 09 Apr 14 at 6:15pm
	320 is not just clearer 106 -it is a completely different animal. 320 is generally a higher spec system. I would go for what Andy says, he knows, as he has worked with most of the systems (- I just formulated them.)

Reuben T Send Private Message Find Member's Posts Groupie Joined: 22 Mar 13 Location: Lyme Regis Online Status: Offline Posts: 74	Post Options Post Reply Quote Reuben T Report Post Quote Reply Posted: 09 Apr 14 at 7:22pm
	the pumps that can be bought with West are really useful and mean that you can get the perfect ratio every time without gaffing around with measuring/weighing(very good in a panicky situation with curing epoxy).