Need some epoxy imput

[Mark Gudschinsky]

Alexander and I bean gluing up his Amphora last Thursday, (4 full days ago.) The epoxy has yet to harden. The leftovers in the mixing tub has a least partially gone off but is still sticky, pliable, and bendable. So the question is, Do we sit on our hands for a few more days, or do we take it apart and try again?

The details: We used fresh West Systems 105 resin and slow hardener. We were careful with the 5 to 1 mix. We had all new pumps and containers, etc. The shop temperature was bout 70 F during assembly, and near 80 F for the last two days.

I used West Systems with fast hardener on our Weekender and never had a bit of problems.

Opinions -- suggestions -- We have some impatient kids here!

[ken connors]

if it was me, id look thru the plans to find something to keep the kids busy. id give it more time just cuz i hate doing things over again. it should have kicked by now at those temps, but hey, whats another day or two :?

[Greg Luckett]

Mark,

You used one pump of resin to one pump of hardner, right? The West pumps automatically make the ratio. If you used 5 pumps of resin and one pump of hardner, then you will have an improper ratio and it may never harden.

Greg.

[Charlie Jones]

Mark- I use slow hardener all the time, even in the cooler weather here. I get at least a partial cure in 24 hours even in 40, 50 degree temps.

I think you got a problem.. I suspect you mismixed. I would think you most likely will have to break the joints apart, clean them up and reglue. I'd bet Greg is correct- mis pumping. It's really easy to do.

[Ed Jones]

I agree with Charlie and Greg, you will most likely have to start over. This time don't trust your pumps to measure, just use them to dispence the epoxy into a mixing cup with graduations marked on it. Dupont makes a good one that can be bought cheep at an auto paint store, about $1.00 each. What ever you do don't use Ever-Coat mixing cups they don't work good. I have learned the hard way on this advise. :?

[Mark Gudschinsky]

Well it appears if Greg is correct about the pumps, then that's the problem.

I'll double check the amount the pumps dispense and go from there.

Thanks all.

[Greg Luckett]

I use the West System pumps for measuring all the time without a problem. No need to measure in a cup. The pumps are calibrated to dispense the correct ratio.

I think the Raka pumps are 1:1 and you must measure in a cup to be sure it is correct. I think System 3 also is that way?

[Charlie Jones]

Ditto on the pumps. I've got mine set on a five gallon container. I also use the MAS pumps when I'm using that epoxy. That's the only way I dispense epoxy unless I'm using LARGE amount. Then I measure with a marked stick.

Here's what my epoxy cart looks like. It's on rollers so I can take it anywhere in the shop. Roller covers, brushes, stir sticks, etc are in the drawer. The top is formica covered and waxed.

[attachment over 4 years old deleted by admin]

[Jack Gardiner]

I agree also,

Been using west for years, I have been building in a heated while im in it shed, and the temps at night have gone from -0 temps and up to freezing, I have come out to frozen epoxy, heat it up and it takes off! Im using med also as I have a gallon of it. also running off the 5 gallon pumps.

Jack

[Frank Hagan]

Pumps can create problems for you if you aren't careful. The RAKA pumps are calibrated for the 2:1 ratio, but you are assuming you are getting a full pump's worth out of each.

I use pumps, but pump into a quart sized container with markings on it. After I pump in the resin, I look at the markings ... then pump in the hardener and I make sure the amounts are correct.

Resin sometimes gets thick in the pump tube, and you don't get a full squirt. The stuff is so expensive I don't think its much trouble to double measure it (sort of like "measure twice, cut once").

[Mark Gudschinsky]

Well the problem is fixed. Greg was right. I was so busy getting rubber gloves etc. on the kids I didn't do a decent review of directions.

Tonight I took apart the assemblies, used a razor blade to scrape off the badly mixed epoxy (luckily it was still entirely soft!) Then I remixed and reassembled.

5 days later, back to where we were.

Lets see? How does that go? The slower you go the faster the boat gets built. :roll:

[Charlie Jones]

Glad you found the problem Mark.

Hey - I once glassed 6 - 8 feet of trimaran deck with no hardener at all in the resin- screwed up a good chunk of glass which had to be thrown away.

What's the saying? The hurrieder I go the behinder I get?

[Greg Luckett]

I vaguely recall someone saying in a news group that you could put a properely mixed batch of resin and hardner over the batch with a wrong ratio and it would kick off the first batch and all of it would harden. I have not tried that but it might be fun to experiment with.

[Mark Gudschinsky]

Well Greg we'll see if that works because that's what I did.

[Simon]

Hey Frank, anyone ever tell you that you look alot like Mel Gibson?

[Frank Hagan]

Hey Frank' date=' anyone ever tell you that you look alot like Mel Gibson?[/quote']

Handsome devil, aren't I? :twisted:

Just thought with everyone putting their picture up, I'd put one up myself. Couldn't find one I liked, though, so my wife suggested I use this one. Hope she still remembers my name ...

[Simon]

Couldn't find one I liked, though

Reallly? I thought you had plenty of great pics out there ... how about this one>?

[Charlie Jones]

Mark and Greg- overcoating a bad mix with a good mix will do nothing but waste the new epoxy. It ain't gonna cure. All that will happen is the new stuff will cure over the bad and you'll STILL have partially cured epoxy under there with no strength.

Epoxy isn't like Polyester. The Hardener isn't a catalyst- it's a required part of the mix to allow proper crosslinking. Polyester will eventually cure even with NO MEKP. Epoxy will not.

Sorry Mark- you best clean the uncured epoxy off and reapply proper stuff.

One thought- do YOU want to spend the rest of the time you have those boats, wondering if THAT join is gonna come apart or not? Especially with one of your little dolls IN the boat?

[Mark Gudschinsky]

Charlie,

Here is what I did:

I disassembled all of the pieces. Then I used a razor blade as a scraper and removed as much of the missmixed epoxy as I could. (I'd like to say all of it but I would be kidding myself.) The Fir for the keel was pretty clean but tacky when I was done. The plywood obviously had missmixed absorbed into the grain (mahogany.) Unless there is a chemical cure for the problem (chemically removing the missmixed.), I think it's as god as can be done.

When I'm sure the current fix is well cured I'll conduct a test for strength.

[Greg Luckett]

Mark,

I hope that works out for you. I suspect we all share the dislike of wasting material and doing rework. As far as I know, Acetone is the only solvent for epoxy. I would not want to use that to clean the wood. This is just speculation on my part since I have not tried it.

Those are great pictures of Alexander and Laura. My boys will be very pleased to see them this evening.

Greg.