Installing Powercrete on Field Joint Coatings in the Field
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| Powercrete R95 Hand Applied in the Field |
Whether you're hand applying Powercrete J, Powercrete R65/F1 or Powercrete R95, there are a few things your crews can be doing to be as efficient as possible in terms of labor costs and material waste. I will divide these simple tips into two families:
- Material Kit Size Selection
- Crew Organization
First: selecting the correct kit size for your project. This one is CRITICAL! Every kit that is purchased will have a pot life that begins the very second it is mixed. That pot life can vary, depending on what the ambient temperatures are outside, what the humidity levels are, what method was used to mix the epoxy, whether the kits were kept in a heated or cooled truck or trailer - etc etc etc etc. All are huge factors. We can't analyze all of those factors (or any of those factors) within this article really. But we can look at the FIXED aspects of your project --- and analyze accordingly.
What are the FIXED data points on your project? You are working with a 16" pipeline -- AND -- the specification written by the owner of the pipeline indicates that the Powercrete product needs to be at least 30 mils thick. I can see from my coverage chart that in terms of volume, 1.85 pounds of material are needed to coat one linear foot of 16" pipe at 30 mils. That is actually a pretty nice fit. Some of the material will end up on the ground; the coating will also be thicker than 30 mils in some places --- so to me personally - if your crews are reasonable experienced; one each 2# kit is likely the perfect size IN TERMS OF VOLUME.
But, with Powercrete J and Powercrete R65; you are very likely to need to put on to layers of epoxy and build up to that 30 mils. Epoxy layers can't be "built" until the prior coat has reached the gel state. So in that case - depending on your weather conditions - you may find in the field that working on two joints at a time works best. You may find that you put the initial layer on the first joint with approximately half of the 2# kit. Then you take the second half of that kit and you put a base layer on a second field joint. You would then come back and mix a new kit to put the 2nd layer on both of those initial joints.
So in those cases where your crews will essentially 'coat two joints at once' -- you must make sure you have two joints welded, cleaned and preheated --- ready to go. Otherwise you're going to have epoxy cure in the bucket during the downtime.
