Recirculating Heater Versus Bigger Pump

Finishers look for most practical adaptation for spraying in cold conditions. June 22, 2012

Question
We're currently using a CAT 14:1 and two Kremlin 10:1 AAA pumps. We spray both water and solvent. Parts are kept warm (+/- 60 degrees) until they go into the cold booth after which they move into a warm drying room. We probably spray around 500 gallons a year.

I was told by a vendor that a UL listed heater and recirc setup would be around $4,700 but that I should consider trading up to a 20:1 pump for our opaques (typically Clawlock and Resistant). We would continue to use the CAT for clears.

My understanding is that the heater would reduce the viscosity and the bigger pump would provide more headroom for atomization of the pigmented coatings. It seems like both would reduce or possibly eliminate the need for reduction. If we're going to heat I'm not going to just warm the pail; I would buy the recirc set up. The lower viscosity of the warmed material might allow us to keep the pumps we have. The heater would hold extra catalyzed material which would be wasted.

If it's the case that the ballpark prices I received are right and the resulting finish would be the same, then I would just trade up to a bigger pump. Unfortunately, I can't afford to do both but I'm willing to do either if it improves our finish. I'm not unhappy with the results we're getting now but it's easier to get what we really want in the warmer months. I don't think we'll have the option to demo a heater but should be able to demo a bigger pump. I'm trying to decide on which way to go, so any reflections would be helpful.

Forum Responses
(Finishing Forum)
From contributor M:
I do not do production work, but I have tried to spray heated pre-cat (wrap around drum heater) at 100 degrees. My 10-14 Kremlin freezes up and requires a strip down and total cleaning. It does not seem to be a clogging problem, but maybe a shearing issue. I have shot finish with an ambient temp of 100 degrees and do not experience the same problem?


From contributor Z:
What about putting the pump/finish in one of the heated rooms, and getting a longer hose? That could be a cheap solution.

From the original questioner:
Thank you. I want to invest the couple of thousand dollars it costs to get the best ROI for us. At this point I'm leaning toward the bigger pump. Perhaps a demo will settle the questions I have. However, I'm intrigued by the heater solution and haven't found much data at all by which to evaluate this.

From contributor J:
I spray CV clear and pigments with a CAT 14:1. I mix up 1 gallon at a time and pre-heat a little with a magnetic engine block heater (only a few minutes). I then place the gallon can in an empty 5 gallon pail with some duct insulation wrapped around it and place the heater under the 5 gallon pail. I hold the gallon can up off the bottom with some wood blocks. This makes a sort of double boiler affair. This just keeps the material 70 degrees or so. I find that this is enough to decrease the viscosity and improves the final result. I am very happy with the finish I am getting.

You could also do yourself a favor by using Becker Matador and ditch the Resistant. I had trouble with Resistant in colder months.


From the original questioner:
Thanks. We set up an entire metal locker in which we placed the pump and the material to keep it warm and it helped. However, when not spraying the material in, the line cools down, which changes the atomization. I'll try out the Matador. Do you use the Becker primers as well?

From contributor H:
You don't need to recirc. More dollars to flush. Just set the heater at 90 degrees and unplug the heater 20 minutes before you get done spraying to let it cool off naturally. Somebody is trying to sell you more than you need. You can get a Binks heater for about 1300 bucks or less. The Kremlins are much more than that plus parts are more expensive.

The bigger pump means more life and it doesn't need to work as hard as the smaller pumps. That is a good move and it is big enough to supply two guns easily.


From contributor J:
Yeah, I use their Unisurfacer for pigmented primer and Care Seal for clears. If the material sits in the line and cools off, take the tip off and recirculate back into the bucket.
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