Cleaning West System Pumps (reprised)

[Guest]

I know folks here use various brand epoxies, and weigh their resin mix on a scale or in graduated cups. I like the ease of West System pumps, especially for one pump batches on little jobs, but the pumps require occasional maintenance.

It was time to clean the West System pumps again. It had been too long; maybe 3 years for one pump. That rarely used 205 fast hardener pump was sticky hard to compress and dispensed a suspiciously small amount, even with some half-pump priming.

I needed a one-squirt batch for something unimportant so I chanced it, kept pumping dribbles and guesstimated the hardener amount. The epoxy set up fine, but I don’t want to do that again. Time to clean the pumps.

West System technical services recommends:
To clean the resin pump, flush it with a solvent - lacquer thinner, acetone or denatured alcohol. West suggested alcohol.
To clean the hardener pumps first flush with hot water (the hardener is water soluble) and then with alcohol.

I had spare cleaned pumps for everything. I had a pump break irreparably years ago while making a pot of epoxy, and hunting down graduated cups in the middle of an epoxy job sucked. Waste of time and a pair of gloves.

I had checked ratio calibration on those pumps the last time I switched them out for cleaning (easy to check during the alcohol flush), so I screwed on new ones and set the old 205 and 206 pumps in a bucket of hot water to soak. Don’t really need spare pumps to clean a set, the rinsing and flush squirting takes only a few minutes.

On removal the 205 fast hardener pump was dark gummy sticky, and the 206 slow hardener pump, which still seemed to work fine, had some white crystallization forming, above the”waterline” as it were.

Couple minutes soaking in a bucket of hot water (I wanted to clean the caps and threads too) dissolved 99% of the crud and I ran a rag around the cap to remove the rest. A few alcohol pumps and they are clean as a whistle, with like new action.

I really should clean and check the pumps as soon as they first become sticky recalcitrant. Or somehow before they become sticky recalcitrant. Maybe annually every spring, when warmer weather brings more frequent epoxy work.

I should date the pumps. Really should date my resins and hardeners too, but I don’t remember when each of those cans were purchased over the years. The pumps at least are now dated, so I will know when they were last cleaned/installed.

The next time I buy resin or hardener I’ll date those new cans as well. I expect that may be common practice among epoxy users. Someone could have told me 30 years ago. Someone probably did; I’m a slow learner.

 

[Jim Dodd]

Simply, Pumps suck !
Either weigh your epoxies, or use marked cups ! The Burping of these pumps is annoying and delivers inaccurate amounts !
Do yourself a favor Mike, don't use pumps for measuring epoxy !
I don't !

Jim

 

[Iskweo]

That procedure has saved my day many times Mike. I did them all in Feb as a matter of fact. I like the ease of use with pumps, even if small batches are tricky.

 

[memaquay]

Geeze, you guys are frugal. I just buy new ones.

 

[dougd]

I do the same with my pumps. A quick dousing of acetone and then water filter through several times before I leave them to dry out for a while. I do have brand new ones stowed away in the event one craps out.

I do a lot of small jobs so the pumps work best for me vs measuring out into cups like you do Jim. If I were to do a large job I could see doing it that way vs a pump. Each method has its advantages and disadvantages.

dougd

 

[Jim Dodd]

I do the same with my pumps. A quick dousing of acetone and then water filter through several times before I leave them to dry out for a while. I do have brand new ones stowed away in the event one craps out.

I do a lot of small jobs so the pumps work best for me vs measuring out into cups like you do Jim. If I were to do a large job I could see doing it that way vs a pump. Each method has its advantages and disadvantages.

dougd

I have a bunch of plastic cups, that have markings in standard and metric, at a 3 oz max. ( From a medical supply source) The metric measure works great for a mix of less than an once.

A small digital scale can work in very small batches also !

Acetone is a carcinogen, worse than epoxy ! I hope you take proper precautions when cleaning with it ! I like having you around !

Jim

 

[stripperguy]

I gave up on pumps many years ago too messy too inaccurate
For larger batches I use a single graduated cup
I have found that too much stuff gets left behind in individual measuring cups
For small batches I use graduated syringes each syringe holds a max of 2 oz

 

[latremorej]

I'm with Jim on this one. I save all of the old yogurt, I can't believe it not butter, and other shallow containers for epoxy use. I find a food scale is plenty accurate and not too expensive. For the price of a replacement set of pumps, you can buy the scale at Wally world.

Jason

 

[Fitz]

Acetone is not yet considered to be a carcinogen.

"Acetone has been studied extensively and is generally recognized to have low acute and chronic toxicity if ingested and/or inhaled. Acetone is not currently regarded as a carcinogen, a mutagenic chemical nor a concern for chronic neurotoxicity effects."

 

[Guest]

I didn’t intend to stir up pump controversies, and don’t have strong opinions about weighing, measuring or pumping. I just thought the cleaning suggestions from West System would be helpful for folks who do use pumps and want to assure clean pump action and calibration.

For my typical epoxy needs pumps are useful. I have never built a canoe from scratch, and my epoxy uses are typically for small repairs, patches and outfitting, often using an ounce of epoxy at a time, which is as simple as a single pump of resin and a single pump of hardener (that’s actually 0.9 fl oz of epoxy). Splurt, splurt, mix, done, all with one un-graduated cup.

The failed hardener pump ounce was for a stair tread on the deck, where an ounce was plenty. My bad for not cleaning the pump on that little used fast hardener, even after I realized it was getting sticky.

I will be measuring epoxy soon. I have the last dregs of resin and hardener in old cans taking up shelf space. The remains in one can of hardener have gone dark; I know it will still work, it just won’t be pretty. I’ll warm those old cans in a pan of hot water, pour and mix by volume and paint them on something.

Not sure what, I have a nicely cut stump from a dead pine on the edge of the driveway that may get a layer of dark epoxy mix on the flat top. Any other ideas? I could just pour it in the pot and make a hockey puck. Or pour it in a Solo cup, let it harden, top it off with an inch of beer and hand it to someone (CWDH).

That procedure has saved my day many times Mike. I did them all in Feb as a matter of fact. I like the ease of use with pumps, even if small batches are tricky.

Christine, my fresh pumps are now dated 4/19, so I’ll know when I last replaced them. I wish the cans of epoxy were likewise dated. Dating the cans may not be an issue for folks who go through lots of epoxy, but for my little drib here and drab there uses a can of resin lasts a long time. Once I have a can of 207 the three cans of different hardeners will be around even longer, and I’ll really want to know the dates of all the cans and pumps.

If I need a truly tiny amount of epoxy, like a pencil eraser sized dab, I just use G/flex. If the single pump ounce is too much I try to have something else prepped and ready to go to use up the wee bit of excess. Actually I try to have something/anything else ready when I use epoxy; even what is left on a brush gets smeared on something, often the bottoms of sawhorse legs.

One additional note about cleaning pumps, make sure the vent hole on the hardener cap isn’t plugged up.

Geeze, you guys are frugal. I just buy new ones.

Looking at my spare pumps I have bought three sets over the years. I know because I have three brand new never used pumps for 207 Special Clear hardener, which uses a 3/1 mixing ratio, and have never had any 207 in the shop. But next time I need to replenish resin I may buy some, if only for the 207 UV inhibitors (and to finally use one of those pumps).

At $15 for a set of pumps that’s $45. That is a case+ of Hippie beer in brown bottles, or two cases of Yuengling.

The pumps are so easy to clean I shouldn’t need to buy a new set of for a long time.

 

[Jim Dodd]

Acetone is not yet considered to be a carcinogen.

"Acetone has been studied extensively and is generally recognized to have low acute and chronic toxicity if ingested and/or inhaled. Acetone is not currently regarded as a carcinogen, a mutagenic chemical nor a concern for chronic neurotoxicity effects."

I do see it still sold as a Nail Polish remover ! But have seen others toot it as a carcinogen. Not having a chemical background, I've avoided it as much as possible. It can make a mess out of plastic gloves, I guess that's good enough for me !

Truely ! Thanks for your Input Fitz ! Good to know.

Jim

 

[Guest]

I do see it still sold as a Nail Polish remover ! But have seen others toot it as a carcinogen. Not having a chemical background, I've avoided it as much as possible. It can make a mess out of plastic gloves, I guess that's good enough for me !

I always have a can of Acetone in the shop, but use it sparingly and with good ventilation. If I want to get stoned up I have other methods.

It will eat some plastic cups. And can make a dissolved mess of cheap Dollar Store disposable gloves. Thanks Doug, I guess you owed me that after receiving the box of purple Nitriles with the razor blade split middle finger. Gawd, I haven’t laughed that hard in a long time.

It flashes off quickly, but puddles of acetone left in a Royalex boat can be foam core death, even with intact vinyl. One fellow accidentally knocked over the can, left inside the hull, with the cap not fully unsecured, before he called it a night.

Next morning it had eaten a hole in his RX hull. Once it gets in the foam core it doesn’t stop spreading. If there is any vinyl split or worn exposed core in RX canoes I avoid acetone entirely.

When I need to remove some old outfitting smutch I start with the least aggressive solvent and work my way onwards; alcohol/mineral spirits/lacquer thinner/Naphtha, etc.

Provided the area is sound, a fresh coat of contact cement is handy for removing old contact cement residue; just paint it on, let it start to set up tacky and rub it around like a giant sticky eraser.