Given that you mixed up 12 oz and then put cilica in it ......... enough to make mustard I suspect #1 you spent way more than 10 minutes mixing let alone trying to use the stuff.

Then there's the thing, #2. Do you have the pumps? Do you have them in the correct jug?  This is a truth thing whether you are using Mas or West. The ratios are fixed.....and work....if the pump in the right place. AND you put one full squirt of each. Note resin will be a long slower squirt with hardner a full stroke which is a short little squirt. (ie 2 to 1) Suspect #2 is you put too much hardner in there.  Resin first then hardner.

I rarely mix more than five "squirts" for joints and never......no .......NEVER.... 12 oz. Its too heavy for one thing. 

Navy and Marine?..........fooled me sounded like Army.  

Grumpy,

USAF

well.....

here's what clearly worked right - you had the right ratios of hardner to resin becuase it worked - it kicked and solidified.

what isn't clear here is did you maintain awareness of how many minuteds you spent mixing the resin and mixing in silica becuase when epoxy 'kicks'  epoxy goes from liquid to hot and solid very quick....especially in a cup.

that said, to have the maximum working time there are several things you should consider:

- use slow hardener (not sure what hardener you were using).  i always use slow because it gives me more working time.   

- use smaller batches.    i actually don't think 12 oz is a particularly large amount, but it's enough that if it is in a cup, when it kicks off it is going to happen fast and its going to get hot.   

- if its a large batch, get it out of the cup quickly.  12 oz in a cup, while not a large amount in my book, is something that as soon as i am done mixing, i want out of the cup so that it won't kick quickly.  i will sometimes pour it off onto the boat and then move it into its final location or pour it off into a shallow pan or into small batches in several cups....anything to avoid a deep cup which tends to kick off very fast.

you will inevitably develop experience about how many minutes of working time you have before it kicks and how a cup full of epoxy behaves vs the same amount of epoxy spread quickly and thinly into a glass layer.  like i said, you probably lost track of time.   so a watch and being aware of how much time is being used is important.  you can also do a test run to see how it all works.  it wastes a bit of epoxy.....but its something that you need to know.   after that, you will develop techniques and a general awareness that will, hopefully, allow you to finish your steps before the epoxy kicks.

for whatever its worth, my first boat epoxy batch had to be kicked out of my garage.... hot, hard and smoky.....i was just glad the wife was not around to see my appoplectic behavior or deal with the fire department.

sounds like a great story:)

h

Dutchboy:

Please keep us apprised of your progress and entertainted by your excellent prose!  Boatbuilding is about building good stories as much as it is building good boats, and I, for one, would like to hear them all.  <;-)

.....Michael

P.S.  Take heart.  I believe you will soon be boatwrights, even though you feel more like boatwrongs at this early stage.

The smoking hockey puck is an epoxy builder's rite of passage. You are now truly initiated. I had ordered an evaluation kit from System 3 before I started actually building my boat and did the same thing - mixed up the entire 8 ounces all at once in a cup. It was a warm spring day so it kicked before I had a chance to do anything with it. It ended up like Howard's, quickly moved out of the garage before it could burn the place down or poison me with the toxic fumes.

Fortunately, it was the eval kit, not the stuff I needed for the boat. While I had been hoping to learn about how to use epoxy, I learned instead about how to not use it and that was almost as good.

Welcome to the family,

Laszlo

   @ Dutchboy. Been there done that

https://www.clcboats.com/forum/clcforum/thread/46297.html

Never built that boat but 12 sounds like a lot. Surprised the directions had a recommended amount mine didn't so I learned the hard way. Do yourself a favor and write a lot down on amounts you use for certain procedures that get repeated in the build same for paint and varnish.

Also as h points out the mixing vessel is key. I learned quickly to use wide flat containers ie tuna fish cans Chinese take out dishes. Or pour out ASAP if possible.More area to dissipate heat extends pot life. Also shop temp and temp of the material itself plays a big part.

Glassed my deck on a hot day in a closed garage epoxy kicked before I was done and made a mess to the point I abandoned my intended bright finish on the deck. Never fear though every mistake can be corrected. Looking good now in Pettit Platinum I'm starting to actually like it better. 
https://www.imagevenue.com/ME133O8C

Hang in there and good luck with the build it'll all work out and come here for help, lot of good helpful guys here

P.S. I've learned one thing here, if you get stuck just think WWLD

   Yeah, it will do that. Usually epoxy is spread right after mixing which helps it keep cool so it won't kick too fast. Adding thickening agents seems to accelerate this some, Maybe it holds in the heat a bit.

What you had there, with that amount of epoxy/thickener, was an "end pour" which is used to reinforce the ends on kayak builds. If you look that up in the forum you will see there are a number of issues and solutions to deal with them.

The best tactic is small batches that can be used immediately. Also, a heat gun can do miracles with lumps ot cured epoxy. Take heart, it's an adventure.

Rites of Passage... that we survive and perhaps learn from, yeah.

It was nearly three years between arrivial of my Waterlust kit and when I actually got started putting epoxy to okoume ply, and that time was well-spent trying to read up as much as I could with stuff here (and elsewhere) that filled the gaps in my knowledge.

First off I decided to start off small. But as I was also choosing to commence with MAS fast hardener there was good reason in that decision. Get a feel for how the mixed stuff behaves at the temps I had to work with.

Later as I acquired confidence and routines for handling the mixing part I got up to batches for pre-coating and 'glassing using twelve to ftfteen pumps, arguably a largish batch for the scale of these kits. But they all went on PDQ & I have yet to struggle with removing a batch gone too fast... thankfully.

Thickeners seem to make batches move more rapidly towards solid-state condition I've noted. I've had small amounts thickened with cellulose and wood fibers begin to warm while still in the small syringes I've been using to fillet panels. I'm guessing it's their insulating properties that affect this, so best mix smaller batches and have a clear path to getting them placed, again mindful of workpiece and workplace temps all the while.

Some of us jump in head first, while others just sample with their fingers, mayhap a thermometer for the very cautious.

Yet the mean goal is to have fun, right?

   Welcome to the brotherhood of the smoking puck!  I did a skerry a few years ago, and a Kaholo last year.  I've never had the guts to try to glue up all the puzzle joints at once.  I took my time and glued up them up one pair at a time. On the skerry, I could do the port/starboard pairs together.  And still had some trials getting them flat.   I did a canoe ages ago w/ the old style scarf joints, and those I stacked together and screwed down, but buttering the flat scarfs w/ epoxy is faster and easier than spreading the glue in all the fingers of a puzzle.  

If you have the slow hardener, then you likely just took too long stirring up the batch and it was fairly large so the evolving heat couldn't escape as well (volume/surface area ratio) as from a small, shallow batch, accelerating the cure.  I've had a batch in a deep paint cup go so hot, it did a little volcano complete with spewing smoke.  Although, that was West System w/ a faster hardener.  If you have medium or fast hardener, then you will have to do small batches really fast unless you like working in temps below 50 degF.  

After engaging the enemy yesterday we have learned he is us...

Thanks to everyone for the great advice. Armed with our new found knowledge the PhD has dispensed with the written instructions and used crayons to produce a picture story book that this Marine can now easily follow. (Disclaimer...some crayons may have been eaten in the development of said book).

Tomorrow we will re-engage and attempt to establish a beachhold on 1 joint...using a minimal amount of epoxy and silica. If successful we will assault the remaining joints over the next few days. 

Our "hockey puck" now has a place of honor in the bar downstairs...we are appropriately proud to have joined such a distinguished order. We are humbled.

For those technically minded...we are using the MAS products from CLC including the SLOW hardener and adhered to the proper pumping schedule.

SITREP to follow once we have contact.

Cheers, Dutch

Wow... slow hardener & you still suffered an exothermed batch?

What kinda temps you workin' in, TX or S. FL 70's+?

   Not long ago I read here in the forum an interesting tip about using CA to join the finger joints, and it seemed like a lot of the posters in this thread were ones commenting about that. I can't find the thread now, but as I remember it, the idea was to join with CA and leave the strength application to the glass. Sounded simple and epoxy- conserving, but has the drawback of not creating the fore- mentioned bar-decorating stylish flaming hockey pucks. Unfortunately I'm already past that step, but it may be helpful for where you guys are at.

   My first time using Epoxy back in mid '80's....Florida day in Mmay, probably 80-85F.

Was stirring the first batch and the stick got harder and harder to stir, finally put it outside and watched it smoke. Crap how am I going to use this miracle stuff? (previously had used polyester for puttying the transoms assembling hulls and decks and a botched job covering a plywood hull that all the glass peeled off)

I called Glen-L whose epoxy I used and they said to keep it in fridge until using, (cooler worked for our rental garage) Then mix and pour out to spread instead of a deep pot ( I used a cookie sheet,worked well as a roller pan and keep it on ice also till using)

Boat turned out well, and I've used these tips with different brands of epoxy on all my builds since with good results.

   @ please don't sink

see the link in my post above that might be the thread you recall.

   Ha! That's nothing! One time I wanted the epoxy thinner for some reason. I put the pot of mixed epoxy in the microwave for a short time, it came out nice and warm... and getting warmer. By the time I got it outside it was starting to smoke.

If you don't have a cabinet scraper get one. They are magic on green epoxy and help on cured epoxy to a degree.

Auto I agree with your suggestion for cabinet scrapers, and will expand on it to the degree that they're absolutely essential even with working on well-cured epoxy. You can focus their contact at the point of the problem with little to no effect on surroundings once you're comfortable with their use. Helps too knowing how to put a proper burr on their cutting edges too. As with any edged tool they can and do get dull.

As for thinning epoxy... no, a microwave isn't recommended as you've learned. If using MAS epoxy, the tech folks their suggest thinning with Xylene, a flammable solvent available in most hardware stores. It doesn't take much (they tell me lots of customers who spray their epoxies use Xylene as a thinner for this) and the required time for the solvent to evaporate out will have to be accommodated too, but it's safer than any other solvent that might be used like Acetone or denatured alcohol which may harbor contaminants not listed on the labels.  

I always mix resin and hardener in one container and after adequately stirring immediately empty the mixture into a pie plate or similar large flat container and add the silica or wood flour there, where the heat can easily dissipate.