Boat building Epoxy

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Dan_Cousin

Well-Known Member
Joined
Jun 5, 2004
Messages
645
How does System 3 and Wests system epoxy compare to the ole LHS 30 minute epoxy?

I know a lot of you guys have switched to West or system 3 and I like your input on the improvements from 30 minute epoxy.

In particular I'm looking at the following attributes:

Shelf life once opened?

Easy to spread inside the engine compartment?

Long woking time? is it adjustable with the amount of hardner?

Resists cracking and letting oil get into the wood (engine compartment again)?

Sandable?

Turns yellow or amber after a year or so of exposure to fuel, oil and water?

Light weight?

thinner or thicker than 30 minute?

Relatively small quanties avaialble for a hobbiest building maybe 2-3 boats a year.

Anything else you've noticed that makes these a better product for boat building than 30 minute epoxy.
 
I would never use two part 30 minute epoxy when building a boat. I have used West System and love it. I am now using MAS epoxy which is thinner than West, with more available cure times. They have a 24oz kit that will do a few boats. Best thing about MAS is you do not need to sand between coats.

Brian
 
West Systems' Pro Set epoxy is the best resin I have used for boat layup. I have built at least 100 Leecraft tunnels with it and it wets out easily, has a long working time depending on hardner, sets in fairly low temperatures, and lasts forever. We laid up the boats, let it set for an hour or so then set the resin in a simple "oven" at 120 degrees. The resin is hard in a few hours. I was going through 5 to 10 gallons a year, but I have had the last of the resin for 5 years since I stopped laying up lots of boats. I can't recommend building important structural things with it, but it still sets up as well as it always did.

Lohring Miller
 
They are by far superior compared to 30 min.

I also never used a 30min epoxy only 24hrs(long set).

NHP is the one I have used among other brands with great results and for sealing the fininhing Z-poxy resin and till now my boats are ok!

Gill
 
The last time I used 30 minute epoxy in building boats was when I first started building around 1970. That stuff was pretty much junk after the first exposier to the fuel and racing. My sister was using the West System stuff (don't remember time frame - early 70's) with 40 ft Chris Crafts. I tied it and never looked back.

I have tried the CA glues. They are quick and help cut the build time a bit. However, the CA release - disolver is nitromethane. You have to seal the joints really well (use the West) so the fuel doesn't get to the glue.

So much has happened over time with glues that I'm going back and relearning what's out there and what's applicable. I found a site that has lots of information about glues

http://www.gluguru.com/Epoxies.htm

The boat i'm currently building is being built with Hysol.

Jim Vota

They are by far superior compared to 30 min.

I also never used a 30min epoxy only 24hrs(long set).

NHP is the one I have used among other brands with great results and for sealing the fininhing Z-poxy resin and till now my boats are ok!

Gill
 
I am using 3M scotch-weld epoxy glue. I've used it before and even after it cures it still has some flexability. Bonds well to all surfaces that I've tried. I will use that to glue parts together then seal with west thinned down.
 
You must always mix epoxy resin with the proper ratio of hardener. The set time is based on the chemistry of the hardener and the resin. Reducing the quantity of hardener will only make a mess.

You can change the set time of Polyester resin by changing the catalyst ration. The basic difference is that a catalyst promotes the solidification and then moves on to other molecular sites. This is the same reason that polyester resin will harden in an unopened can (very loing set time, but it does eventually get hard). The catalyst just makes it harden faster.

In the case of epoxy the hardener is required as part of the chemistry of the final product. The resin will tend to crystalize, but these crystals can usually be romoved by heating the resin and agitating. The curatives (hardeners) have a shelf life that is mainly due the aromatic amine escape or moisture absorbtion.

The best way to mix epoxy is by weight, though West, MAS, etc provide metering pumps for mixing by volume. Epoxies also can be sped up and/or fully cured with the addition of heat. I have a temperature controlled hot box to post cure my boats at 150 degrees for a few hours. It has an indirect heat source and circulating fan. The key is to not put direct heat on the hull. Direct heat lamps can generate a surface temp over 500 degrees...........

Signed,

ex-composites process Engineer
 
:p

You must always mix epoxy resin with the proper ratio of hardener. The set time is based on the chemistry of the hardener and the resin. Reducing the quantity of hardener will only make a mess.

You can change the set time of Polyester resin by changing the catalyst ration. The basic difference is that a catalyst promotes the solidification and then moves on to other molecular sites. This is the same reason that polyester resin will harden in an unopened can (very loing set time, but it does eventually get hard). The catalyst just makes it harden faster.

In the case of epoxy the hardener is required as part of the chemistry of the final product. The resin will tend to crystalize, but these crystals can usually be romoved by heating the resin and agitating. The curatives (hardeners) have a shelf life that is mainly due the aromatic amine escape or moisture absorbtion.

The best way to mix epoxy is by weight, though West, MAS, etc provide metering pumps for mixing by volume. Epoxies also can be sped up and/or fully cured with the addition of heat. I have a temperature controlled hot box to post cure my boats at 150 degrees for a few hours. It has an indirect heat source and circulating fan. The key is to not put direct heat on the hull. Direct heat lamps can generate a surface temp over 500 degrees...........

Signed,

ex-composites process Engineer


Good repsonses and I just found a West Marine in the same parking lot as my LHS. How about that.

How long does that stuff last once opened. I might build a boat or two then it could be a year or so before I build another one. Would it last this long if kept inside in a closet? what about a unheated garaege in Houston Tx? :p

Any online places with the best price in this stuff or is it about the same as walking in the wests Marine and buying local.
 
ithink you can buy some pumps that will measure the right mix of epoxy, please correct me if i'm wrong.
 
Yes, you can buy metering pumps from the manufacturer, but they sell different pumps for the different hardener ratios. I prefer to mix mine by weight. You can get decent digital scales for less than $20.

As for storage life, it will last longer if you purge the oxygen and moisture out of the can with N2 gass. You can get purge gas at most paint stores. Works great on paint as well. I have shell epon that has been around for over 10 years. It still flows the same as when I bought it. But I have not performed any mechanical tests. I have some unopened cans of West that are 5 yrs old.
 
On the West system , is it a good idea to pull the pumps out and cap of the can and discard the pumps ? Then just buy new pumps when needed .

Just wondering

Ed
 
These pumps ARE NOT CHEAP. I just leave them in the cans and use when needed. As for how much to buy, the resin and hardener comes in three sizes, with the hardener cans being considerably smaller than the resin cans. If you won't use a lot, buy the size "A" cans, which have 32 oz of resin, 7 oz of fast hardener(#205) and 10.6oz of the very slow hardener(#209) Of course, there is a slow(#206) and glassing(#207) hardeners as well, so you can pick what will work best for your needs.
 
Guys,

I use WestSystems exclusively. I keep the pumps on the cans, as the tech notes provided by WS state exposure doesn't effect performance.

Here's a little trick for those who only build one or two boats every once in a while. It really sucks to have to pump out a whole "batch" of epoxy when you only need to glue up a couple little pieces. It also sucks to have to let projects sit around until you have enough of them to justify pumping a whole batch. Here's the solution. Call up a friend in the medical field and have them "procure" a few graduated syringes. Fill them up with resin and hardener (seperately, of course) and dispense a fairly accurate micro-batch whenever needed. I use a 12cc syringe for the resin and a 3cc for the hardener. The larger is graduated by .2cc and the smaller one by .1cc. I can dispense as small a batch as 1cc with enough accuracy to ensure proper mix. The only time I pump a full batch is when I'm sealing or building sponsons (WOF).

Thanks. Brad.

Titan Racing Components

BlackJack Hydros
 
West Systems' Pro Set epoxy is the best resin I have used for boat layup. I have built at least 100 Leecraft tunnels with it and it wets out easily, has a long working time depending on hardner, sets in fairly low temperatures, and lasts forever. We laid up the boats, let it set for an hour or so then set the resin in a simple "oven" at 120 degrees. The resin is hard in a few hours. I was going through 5 to 10 gallons a year, but I have had the last of the resin for 5 years since I stopped laying up lots of boats. I can't recommend building important structural things with it, but it still sets up as well as it always did.

Lohring Miller

I have built a couple of stock outboard boats and have repaired at least a dozen using West System epoxy

and was worried about the structural integrity of old epoxy myself. About the time I was going to

throw some out and order new, West came out with an article in their magazine about the tests they

had done on aged "in the can" resin. They claim that even though the color had shifted to an amber

color, there was no deterioration of the strength of the final product. I figured that since they are

in the business of selling new epoxy, they were doing us a favor by printing this info and have no

problems in using epoxy that was ten or more years old.......not as pretty as the new stuff but just

as strong. Actually, the hardener turns brownish red in color but never had a problem with it setting up.

This article is probably too old to be in their archives on the web site but you might still want to

check the site to pick up a few tips on the use of their products. Here is link to website....check it

out for a lot of useful info and answers to other questions in this thread.

http://www.westsystem.com/

Rick Maston at Maston Marine stocks most of the West System products in smaller quantities and

his website is: http://www.mastonsrcmarine.com/
 
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