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Permalink Reply by lhedrick on June 27, 2010 at 6:55am

I don't know the total amount. Could be a lot for 18 ounce fabric (2 quarts ?). Lets says it's 2 quarts total for a bottom. You wouldn't want to ever mix that much. The larger the quantity the faster the curing reaction will take off. Once it starts generating heat it will take off and become unusable in a very short time. 1 quart of epoxy will start boiling and smoking in minutes.

Work with small batches. I use 2:1 RAKA epoxy and when wetting out glass I always use the slow hardener and only do the work in the morning before the heat of the day. 60 degrees is what I like. Only mix 2 cups total at a time, thats 1/2 quart and as soon as it's been mixed start moving it.

Don't forget the cure window. With slow hardener the re coat window is 24 hours. Plan you work so you will be ready to fill the weave after 12 hours which will give you a good bond. I wouldn't even try to wet out 18 Oz glass in summer with fast hardener. Epoxy is expensive so play it save and get what you need. Epoxy also has an indefinite shelf life and is good for all kinds of things, it won't go to waste so order plenty.

When in doubt test your process. 18 Oz bi-axial his heavy stuff and will be harder to wet out. Kevlar is also hard to wet out. Like I said use slow cure so you have plenty of time to wet out the cloth before the epoxy stops flowing.

It's not hard, just plan out your attack in 12 hour windows.

As for total amounts, I only know about the gross total for everything. I used 9 gallons total on my last 16 footer which was a stitch and glue boat.

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Permalink Reply by chris towles on June 27, 2010 at 8:38am

thanks larry,
i only have the fast hardener. prob should have bought some of the slow when i was down in slc last week. mabye somebody will let me use their cool garage to do it. i had wondered about the whole small batch, small area thing. sounds like it may be the thing to do. 9 gallons is alot of epoxy. i am planning an oiled interior so i probably won't need that much. my boat came with about 3 gallons of west systems. i've got about 2 gallons left which sounds like it should do the boat just fine. thanks for the tips

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Permalink Reply by Dave P on July 2, 2010 at 6:59am

I think I used a gallon and a half on each side of my 18 ft dbl ender floor, (3 total) 18 oz biaxle, and 2,10 oz. cloth. I agree with the other comment about using the slow hardener and working in the morning. That's what I've had to do lately.
Work fast and efficient!

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Permalink Reply by chris towles on July 2, 2010 at 10:39am

the boat is done..last flow coat is on the hull now. i took the advice and have been dawn patroling it the last 2 mornings. i have been using fast hardener and it has been working well. ran out about 2/3 of the way thru my hull layup yesterday and frantically called evry boat owner i knew looking for hardener. got it all sussed out and the boat should have been done yesterday, but i got lazy with my last batch and mixed it in the roller pan. guess i didn't get a very good mix cause it was still tacky this morning and about 200 bugs had met their fate. i scraped it clean, then rubbed it with acetone, and gave the whole hull a quick sand and laid one last finish coat...should be good to sand and fair the sides in a few hours here. i worked in smallish batches..usually about 12 pumps and get to moving it. only tried to mix one decent size batch thinking i could get a full flow coat in one shot, but i had it in the pan too long and it went off wasting about a 10 pump batch. no carnage othewrwise though..hull looks great and very slick

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Permalink Reply by chris towles on July 3, 2010 at 12:28am

guess i spoke too soon on the no carnage part. turns out my last coat didn't kick either. i tried scraping, and acetoning again., then laid another coat .and then that coat didn't kick either. i was thinking the hardener might be bad cause it was so old, but i did get one or two batches that worked out right. i guess mabye the pumps are off or something. all i know is my hull is still a sticky mess, and in all the mele i went thru the last of my resin. have to order more so i guess the launch date is going to be pushed back another two weeks or so. anybody have any tips on getting this sticky mess off my hull and getting the next coat to adhere? could i roll a thin coat of hardener to kick off the sticky stuff then sand it?

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Permalink Reply by Lawrence E. Long on July 3, 2010 at 5:32am

Cris: Some years ago I took one of Jason's courses on building a Freestone at the WoodenBoat School. The same thing happend to me- I screwed up the mix on a sidepanel batch of Raka- medium hardner I think. We laid it out the next morning in the sun- and it still never set up. After a day Jason had us(only 3 in the class) get paint scrapers- not putty knives- and get down on our knees and litterally scrape off the whole sidepanel down to the fiberglass. Sounds like your boat is assembled- might be a little easier not being down on a concrete floor. As I recall after a full morning of scraping we wiped it down with acetone. Let it dry and then mixed up another batch of resin. The stuff we pulled off the boat was like stiff chewing gum- no way you could sand it- the paper would get loaded in 10 seconds. This is one job you will not forget. Whatever you do don't try to spread a coat of hardner on top of the current mess-will not "mix" and create more of a problem.

Try to get a HYDE scraper- the have a good curved handle that is easir on the wrist and a 4 sided blade that you can resharpen-and you have to have them sharp.

This worked for us- hope it works for you.

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Permalink Reply by lhedrick on July 3, 2010 at 2:15pm

Chris

Just like Lawrence a friend and I had a mix error with Raka. After the epoxy would not cure it became clear we mixed 2:1 the wrong way. We had to remove all the glass and scrap down with acetone. The good news is you will get past this after cleanup.
The bad new is it is a sticky mess.

As Lawrence mentions don't try to put more resin on top, strip it off and start over.

Hang in there, it will all work out.

One the mix process always do the same thing. I always start with resin then hardener when using pumps. Don't get distracted or try to have conversations while mixing. Get it right.

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