White foam in floatbox.

[madmapler]

We had an annoying amount of white foam in the flue pan floatbox at the beginning of the season that was so bad that it interfered with the operation of the float. We had to keep cleaning it but now there is absolutely none. I attributed it to concentrating to 20+ brix as this year was a first for that but then it all changed. Does anyone know what causes that?

[DrTimPerkins]

Does anyone know what causes that?

Where are you adding defoamer to the pans? When sap, and especially concentrate, first are heated, you will get a good bit of foaming. This is especially true the first time you boil, or after a thorough pan cleaning. After that, there is residual defoamer clinging to pan surfaces, and less defoamer is needed. We've had rigs where foam is a constant issue in the floatbox. Sometimes adding defoamer at that point will rectify the problem, othertimes not.

[madmapler]

The foam was like white bath suds, only denser and it would overflow the float box. I thoroughly cleaned the evaporator (like an end of season cleaning) during the cold spell and it didn't return. I just noticed after several days that it went away. Come to think of it, the foam came from the raw sap side of the float box so it would have been straight out of the preheater. Sorry, I should have mentioned that.

[wiam]

We refer to it as the foam monster. My 2x6 did it way more than my 3x12 does. Never bothered float. Just made a mess on the floor.

[madmapler]

That's the stuff. No doubt. My float slides on 2 horizontal pins and the suds were pushing it off causing the pan to flood.