I've had that problem and did exactly what you've done - bought a new pump. In fact, I now include new pumps as part of the prep for evey new build. Compared to the cost of everything else, it's a cheap precaution.

The anti-pump crowd will probably jump in to point out what a terrible evil waste of money this is and how much simpler, more reliable and especially cheaper weighing or manually measuring by volume is. But if you're like me and prefer the  smooth work rhythm and workspace savings that you get from a pump, a new set of pumps for each boat (or build season) is the way to go.

Have fun,

Laszlo

PS - what was the temperature in your shop? If it gets cold enough the pump may not be able to pull the thickened liquid fast enough to displace all the air in the usual time

   Thanks, Laszlo.  Having done a little more reading, I've seen reports (possibly here, possibly at Wooden Boat Forum) that this isn't uncommon.  Apparently it's usually the hardener pump that goes bad, perhaps due to some recent design change. 

Anyway, I like your strategy of buying an extra set upfront.  And I too prefer to establish a nice rhythm and work with small, sequential, easily mixed batches.  Also, I don't think temperature is a problem.  When I'm building, I keep the shop at 63 degrees 24/7.

The hardener reacts with air and humidity and I find that it can crust over and clog the tip of the pump nozzle. I use a bit of copper wire to clear the nozzle as needed; the clog is always within the first few millimeters of the nozzle opening.

(Don't be a dummy like me and use the same bit of wire to clean both hardener and resin pump nozzles...)

If the issue seems to be deeper in the pump, do not waste a moment getting in touch with us for a replacement. [email protected]

Behold- the Anti-Pumpite foretold by Laszlo! ;)

After experiencing all of the problems noted above and buying several sets of replacement pumps, I decided to throw caution to the wind and ditch the things. All I lost was the headache. 

I find simply pour straight from the jug results in less mess, better accuracy, muuuuuch faster, and at zero added cost. (And maybe I need to meditate more, but measuring out larger volumes of epoxy one slow, anemic squirt at a time about drove me batty. And if the shop was cool and I hadn't pre-warmed the components- fuhgeddaboudit.)

Some folks use a scale- you can get a digital kitchen scale for less than the price of new pumps- but the reusable cups with graduations you're probably already using (or even old yogurt cups with fill lines drawn in Sharpie) work for me. 

Give it a try the next time your pumps crap out.

Good luck!

Patrick

I’m reading this thread with care, attentive to tips for avoiding ‘issues’ with my first, upcoming build. Only prior experience has been w/ West System pumps anywhere from about 1982 to last project in 2001. Never had issues with ‘em but I’m seeing evidence that scale is workable option, just pour & weigh then mix & apply... saving my 6 oz. yogurt containers I am!

Love the forum. learning lots as I read of others’ experiences.

I'm a fan of using a scale. Zero the container, pour the epoxy in and note the weight, then zero the scale again and pour in half the hardener.

On a side note, I use a smaller container for the hardener so I don't confuse it with the epoxy when mixing. The hardener came in both a 1/2 gallon and 32oz container to go with the 3 1/2 gallon epoxies. After I emptied the small hardener container, I refilled it from the 1/2 gallon container so I don't have to worry about mixing them up.

>>I'm a fan of using a scale. Zero the container, pour the epoxy in and note the weight, then zero the scale again and pour in half the hardener.

Bad idea if your epoxy is supposed to be mixed by volume and the 2 parts don't have equal densities.

Laszlo

This is where graduated volume marked containers work well.

The reall issue is.... unless you're mixing everything in that one "One-Time-Use" container, then you'll have to figure out how to get all the goop out into a third container.  Very small spatuals are great, until you accidentally use the wrong one in the wrong container.

Not to mention the cost of those containers.

I'm still using the Pumps, which haven't failed yet... But it's still early in the build of boat #1.

Also, i have a second set of pumps "at the ready"; so... there's that.   

Good point Lazlo, I forgot to mention that. I compared the weight of the 2 half gallon containers before starting and they were virtually the same so a 2:1 weight ratio works. Other epoxy brands may be different.

   Maybe I've been lucky but I've never had a single failure using a scale.   From generic EPON, and on to the premium brands like Stephenson, Case, West, etc...

If any of them should have failed using a scale generics like US Composites (Epon) should have failed.  They only give by volume mixing instructions.

When we built our PMD take-apart, we bought a bunch of clear plastic food containers (like you'd get when buying potato salad from the deli) to use as mixing cups.  We used carefully measured water to mark one of the cups as a "template" with 2 fluid ounce graduations.  We'd then hold the template cup up next to each new mixing cup and mark off the desired volumes.  Initially, we were just marking the total amount and relying on the pumps to get the 2:1 proportions, but we soon started markng off a level for the resin and a level for the total as insurance against mis-pumping.  Measure twice, pump once?  Belt and suspenders?  <;-)

.....Michael

I'm careful to find out if the ratio is based on weight or volume and then I use a kitchen scale or syringes. Getting fairly thick epoxy into a syringe can be a pain but it is very accurate. Having said that I would really like a MAS epoxy dealer here and be able to use pumps. I can get West Systems epoxy here and they do pumps but it is way overpriced. I envy the range of supplies you guys have in the States.  

I used to think West Systems was over priced.  This is my first experience with them.  Normally if I'm spending $100+ for epoxy it would be Cass' Adtech 820 as it's suitable for resin infusion as well as wet layups.... Plus it has three hardener options.

Where West surprised me is how predictable and fast it would hit a full cure.  Compared to Epon (aka every generic store brand on the planet) it's well worth the money.  Compared to other premiums I'd shop based on CPS, cure time, application type, and obviously price.