problem with epoxy pump

[peterAustralia]

hi all,

I have west system epoxy and the 5ml pump for the hardener is not delivering the right amount. I can tell this visually. The 20ml pump for the epoxy is fine.

At moment I am using a 2:1 epoxy system ( bote-cote) which I have lying around. I would like to be able to use my west system though. I see my options as buy a new pump set ($30+), fix the pump, or find a small balance to allocate the hardener by weight. I am aware I have to compensate for density of hardener.

The pump may be a fraction dirty, however when pressing the pump down hardener only comes out during part of this depression process. Until recently harderner would flow or teh entirety of the down stroke.

I am trying to find cheap balances/scales in Australia that will weigh small weights accurately. This being harder than it as first sounds. Yes I can buy 500g balances for $4, but the division is only 5g, when a unit of hardener weighs about 5grams!

any tips on balances/scales or fixing the pump?

n peter evans

[Bruce Hooke]

I'd start by taking the pump out, pumping it dry, cleaning it with solvent and then re-priming it. While you have it out you can also check to see if there is something obvious going wrong. I think I once had problems with the ball bearing down near the bottom of the pump that acts as the valve getting "sticky" and not doing its job properly (sliding down as soon as you start to compress the pump) and producing results along the lines of what you describe, but my memory could be off...

[JimD]

??? Your pumps are measuring weight? Never heard of that before. Just buy some throwaway graduated cups and measure by volume.

[Dan McCosh]

hi all,

I have west system epoxy and the 5ml pump for the hardener is not delivering the right amount. I can tell this visually. The 20ml pump for the epoxy is fine.

At moment I am using a 2:1 epoxy system ( bote-cote) which I have lying around. I would like to be able to use my west system though. I see my options as buy a new pump set ($30+), fix the pump, or find a small balance to allocate the hardener by weight. I am aware I have to compensate for density of hardener.

The pump may be a fraction dirty, however when pressing the pump down hardener only comes out during part of this depression process. Until recently harderner would flow or teh entirety of the down stroke.

I am trying to find cheap balances/scales in Australia that will weigh small weights accurately. This being harder than it as first sounds. Yes I can buy 500g balances for $4, but the division is only 5g, when a unit of hardener weighs about 5grams!

any tips on balances/scales or fixing the pump?

n peter evans

It sounds as if the pump is sucking air when the spring is returning the piston. I've found that a loose cap can cause this--or a loose pickup tube. The result is a partial fill on the upstroke.

[peterAustralia]

hi all,

I checked the cap and made sure it was super tight. It was pretty good as it was. After pumping 3 times it is still only delivering half of what it should.

No it pumps by volme not by weight. What I meant was that if I proceed down measuring the hardener via weight with a balance, then I will have to take into account density of materials.

Yes I could clean it out, sounds yucky job though.

At moment it seems to reliably deliver about half of what it should.

I have discovered a good ebayer (2000 positive, zero negative feedback) that sells 50g balances at 0.01 g accuracy for $20 Aust ($15 US). This is less than the price of a new pump set. So I will do it that way, buy the balance and determine amount of hardener to add via weight. In theory I can also do very very small jobs, and not be limited to 25ml minimum.

What other applications I have for the balance, I really do not know.

might be best if we please let this thread die..

n peter evans

[duck builder]

Could just be coincidence, but my West hardner pump misbehaved this week as well. I couldn't tell for sure but it seemed that the ball bearing referenced by others seemed to not be doing its thing. Can't say for sure, but maybe some issue with the hardner pumps? I know that doesn't help you. My pump was only about 6 months old. Though a little irritated I did go out and replace it.

[few3]

Bingo, there is a problem

[peterAustralia]

I have now completed buying the balance via ebay,

cost $28 Aust including postage, delievery by Monday (seller in same city). This is less than cost of a new pump set. The pumps sell as a pair, thus you have to buy both of them, even if you only need one.

Now I have to work out other uses for a 100g 0.01g balance..

n peter evans

[few3]

The hardner pumps can be cleaned pump warm water (little detergent). Then pump some iso alcohol or denatured through. Then check the heads. I have old Metal lid West pumps laying around that still meter perfectly, but have had some sketchy mtering on the newer ones. I am not sure who West is having their pumps made by now, but I think the QC is going down. This is one thing I have found on a number of the pumps.

If you remove the yellow heads ( Keep an eye on that steel ball that will fly out and roll under anything within a hundred feet ) you may see this......

http://img184.imageshack.us/img184/5136/pumpuh6.jpg

The part of the pump shaft (blurry, I know) that inserts into the yellow head is crushed over. The stem itself is too long for the yellow pump head, and is smooshed at the factory. The problem with this defect is when you pump, the ball is pushed against the smooshed plastic and can actually get caught on the jagged edges delaying for a split second the balls ability to seat and close the opening. This allow just a moth's fart amount of air into the assembly, but that is all it takes.

If this appears to be the problem after cleaning, and you can't return or exchange it, you can whittle off the rough edge, but if you trim too much, you may have to put a dab of superglue on the neck to tighten things up.

The other thing to look for is crystals ( though I have only seen them in the Resins ).

Either way, Contact West System online. I have give them an A++ on customer service and tech support, they may even give you a phone-call instead of an e-mail response. After hearing Duckbuilders experience, I am going to contact them myself and find out what is happening. Also, check their site out for a measuring jig for small batches.
http://www.westsystem.com/

[boylesboats]

And that why I don't use pumps... They're not right half of time.. I buy those plastic throw aways med cups from a home care store, which have markings on the side in ounces and cc.. I get good batch every time...

[JimConlin]

I had a WEST hardener pump that had an internal spacer which limited the travel. It was a molded plastic clip which clipped over the skinny part of the plunger inside the pump. If it slips out of place, the pump dispenses too much hardener. I don't know whether the newer (yellow top) pumps have this.
To remedy this problem, wash the pump out with warm water and disassemble it. If there's a loose part between the 'piston' and the top of the pump, that's the cuplrit.

I've had one failure like this in 20 years (100 gallons) of using West System pumps. For batches over a pint or so, i measure by weight rather than use the pumps because it's faster, but i know darn well that weighing is a more error-prone process and that one of these days, i'm gonna make a big mess.

[Bruce Hooke]

And that why I don't use pumps... They're not right half of time.. I buy those plastic throw aways med cups from a home care store, which have markings on the side in ounces and cc.. I get good batch every time...

The only problem with this approach is that with 5:1 epoxy you have to mix up a larger batch than is sometimes desirable in order to get enough hardener to allow for reasonably accurate measurement. In situations like this I really like being able to bring out the scale...

[Bruce Hooke]

Now I have to work out other uses for a 100g 0.01g balance..

n peter evans

Scales are useful for all sorts of things...from weighing mail to figure out how many stamps it needs to measuring wood samples before and after oven drying them.

They are also useful for baking, but I don't recommend using the same scale for both epoxy and baking!!!

[epoxyboy]

I have had the same problem - fixed by pumping lots of plain old detergent and hot water in the laundry tub through the hardener pump. You dont need expensive toxic waste epoxy thinner.
I have to say that the more I use WEST the less impressed I am. It is more expensive and seems to be incredibly fussy about resin/hardener ratios, ambient temperature, time of the month and phase of the moon. My previous project built with "Awlcraft" epoxy (may be local to NZ???) and no pumps tolerated fairly indifferent mix ratios (I was measuring the stuff by the capful sometimes) and cured fine in temps ranging from -5C (25F) to 30+C. In similar conditions on my current project WEST cures incredibly slowly (several day in cold temps) to uselessly fast in the hot temps.

Pete

[David Tabor (sailordave)]

Could just be coincidence, but my West hardner pump misbehaved this week as well.


My pump was only about 6 months old. Though a little irritated I did go out and replace it.


The problem lies in the fact that Microsoft wrote the software for Gougeon Bros. and that's what's installed on all the pumps... I heard tell that there was a glitch in the software that caused the pumps to lock up the first week of Feb/07:p :D :D :D

Sorry, couldn't resist!


PS... 20ml/5ml = 4:1 I thought regular WEST was 5:1 ratio???

[Pierre LaRochelle]

Stick to VOLUMETRIC RATIOS when mixing epoxies. Compensating for density is much like using last years tax form.....Good Luck!

pl

[Chan]

Exactly why I don't like west system, as well as the smell. MAS is 2 to 1
just use measuring cups. Takes forever to pump enough west to do anything but glue a scarf together and that's if you can remember did I do 6 resins or 5

[SamSam]

Here's a solution to pumps.... Sam

http://www.duckworksmagazine.com/05/articles/scale/index.cfm

[boylesboats]

Here's a solution to pumps.... Sam

http://www.duckworksmagazine.com/05/articles/scale/index.cfm

Till someone bumped it....

[David Roberts]

We never had any luck with the mini-pumps. Seemed like they'd just wear out or something. There's nothing worse than an epoxy pump you can't trust! The gear pump is the real deal, but you have to use a lot of epoxy to make it worth while. The time saving from using a gear pump is absolutely amazing in a big project, though.

We built a balance beam scale for measuring Resorcinol. That works great. The Duck Works balance seems complicated. You want a 5:1 balance beam, just make one arm 5 times the length of the other arm. Incorporate movable counterweights so that you can balance the two empty containers before adding material. Put resin in the container on the short arm, then put hardener into the container on the long arm until it balances. If you use the same container several times for the hardener, you won't have to be quite as neurotic about scraping it clean. Nothing to it.

The specific gravity of 105 WEST resin is 1.15 while that of 205 hardener is 1.05, so you might want to allow for that. Other SGs on the westsystem.com site. Mix a test batch first.

[SamSam]

We built a balance beam scale for measuring Resorcinol. That works great. The Duck Works balance seems complicated. You want a 5:1 balance beam, just make one arm 5 times the length of the other arm. Incorporate movable counterweights so that you can balance the two empty containers before adding material. Put resin in the container on the short arm, then put hardener into the container on the long arm until it balances. If you use the same container several times for the hardener, you won't have to be quite as neurotic about scraping it clean. Nothing to it.

The specific gravity of 105 WEST resin is 1.15 while that of 205 hardener is 1.05, so you might want to allow for that. Other SGs on the westsystem.com site. Mix a test batch first.

I've seen them like yours. They are much better than the Duckworks one, as any amount can be mixed with no adjustments. I couldn't find any photos or articles to post so I put that in to show that money doesn't need to be spent. One like yours shows not only that, but that you can make one for nothing better than you can buy. Sam

[Tom Mac]

David Roberts, Thanks!! great idea, I had pump trouble, ranout and got a new one, fine. 6 months later, happens again. Now I know what to do. Thanks Tom Mac