West System 205 fast hardener vs. 206 Slow Hardener

[Richie the shipwright]

You should do whatever you need to do to achieve the CORRECT amount of potlife!! Im not suggesting you speed up the cure, just a way to achieve the ideal curetime, as per instructions. Thick (cold) resin takes longer to wetout the glass properly. That means MORE work with your roller.
Work out your potlife, then plan your layup from there.

Just tips from my 20+ years experience... :-)

[Richie the shipwright]

Detox, this is incorrect. the fast and slow hardeners will give you the same strength when cured. The "speed" of the hardener simply gives you more control of curetime. The curing process generates exothermic heat. If there is too much of this heat, the resin will crystalize and become brittle. If there is not enough, the cure can stop entirely. So... Cool day+ fast hardener, warm day+slow hardener. If you are after a really slow cure, use 209 superslow hardener. Either warming the resin in winter or cooling resin in the summer, are just ways to fine-tune " optimum cure time.
If the weather is either too cold+ damp, or too hot and dry... YOU SHOULD NOT BE GLASSING. This is why top quality glasswork is done in a controlled environment. You can cause crystalization even with the superslow hardener if you heat up the curing laminate enough. Five minute epoxy will cure in one minute if it is a hot day... Because the quoted "five minute curetime" is timed at a certain ambient air temperature.
Hope this clears up a few things. :-) The gudgeon brothers book on boat building with west systems is an awsome book to get your hands on. It has been my bible for many years... All the best.

[longballlumber]

The gudgeon brothers book on boat building with west systems is an awsome book to get your hands on. It has been my bible for many years... All the best.

Where can I get one of these books?

Thanks
Mike

[T.S.Davis]

A slow cure doesn't necessarily mean more strength but it does give the resin more time to soak deeper into the grains of the wood. In effect combining the grains of two pieces into a single matrix.

I've used graphite powder as a filler before too. Like granite when it's cured. You end up with a boat that's a brick poop house. Mike, guess which boat is full of graphite. haha

[Richie the shipwright]

You're spot on t.s.!! Increases the density of the wood. Most important factor is that the resin is able to cure fully. In a controlled environment, the superslow hardener will give you a lot more worktime allowing it to permeate further into the wood without any negative effect on the cure.

Mike, Im pretty sure the book is still in print, Should be able to order it from your west systems supplier. Or...you can download a pdf format from westsystems.com Anyone who enjoys building boats should check it out. :-)

[Mike Caruso]

Warming your resin before you add the hardener is also a good idea when working in cool temps. You can do this with a metal can and a heatgun. (dont preheat hardener tho) :-)

Nice tip Richie thanks.
Mike

[T.S.Davis]

Bringing this back for a minute.

I was building a wing for a boat over the weekend. On my kitchen counter so temp wasn't an issue.

Just wanted to say, not every part of our builds needs to be built like a brick.

I was using West and fast hardener from syringes. Pretty precise mixing so I know the ratio was good. The fast hardener has a shorter pot life. Meaning actual work time. But it still takes hours before you can trust it to stay put. So the process has taken me a couple days of tinkering to build what I wanted.

I could have done all the work I needed with 5 minute Loctite and been done with it in a few hours max.

My point is, pick your battles. If you build a boat with 5 minute epoxy (and I have) it will fall apart before you want it too (and it did). If you build a part that has no structural requirements with 5 minute cheapo stuff it can be okay. The epoxy police wont come to your house to punish you.

[longballlumber]

Agree with everything that Terry just stated.... However, I have always used 30min epoxy instead of 5min. I have always been told that 5min isn't waterproof. Can anyone confirm this statement?

Later,
Mike

[T.S.Davis]

Not sure how that would be possible. The two chemicals become a single plastic. It's not water soluble.

It wouldn't soak into the wood very deep at all so maybe that's why some say it isn't waterproof. Your adhering pieces together as opposed to making them a matrix. When the epoxy soaks in the joint becomes- the resin, the fiber from one part, and fiber from the other part. They become one thing. With a 5 minute I'm just sticking them together. If water gets in behind it into the wood fiber it's just a matter of time.

[Richie the shipwright]

All epoxy is only water resistant. No epoxy is totally waterproof.

T.S. Timber coated with epoxy becomes a composite, not a solid. All of this is covered in the book i suggested. By the way, i should add that west systems is owned and was created by the gudgeon brothers. You can absolutely say they wrote the book on this subject.

[bozo586]

mike & terry----believe i have the book you want! called fiberglass boat repair & maintenance-89 pages-9 chapters-great book very usefull. you can copy it if you want-it's by west systems give me a toot for more information.

[bozo586]

correction to post#26--thats wrong book! west systems book(right one)-publication#002-the gougeon brothers on boat construction---available from west system inc. the#for the fiberglass boat repair & maintenance is 002-550 also a great book!

[Richie the shipwright]

No disrespect to you bozo, but i must repeat..... The Gougeon brothers ARE west systems. Their book is 27 chapters with 412 pages. its free to download, has been around since the 70's and is still used by tradeschools today. There is no better book.

[Richie the shipwright]

We're on the same page mate! Thats the one... happy reading everyone!