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Section 49 Question

Stockmanreef

Well Known Member
I am a little confused on 49-06 and 49-07. The plans say to use and RTV on 49-06, but then on 49-07 for sealing off the fins on the oil cooler is says to use a dear silicone adhesive/sealant (not RTV) on the horizontal fins.

The problem is that any silicone sealant that cures at ambient temperatures is an RTV--room temperature vulcanization. While HTV is high temperature vulcanization. So RTV and HTV just relate to the what temperature the polymerization takes place. Generally, RTVs polymerize via reaction of one of the components with water, so that it can react with the other part of the composition. Sort of like super glue, it needs a bit of water to polymerize.

I sort of understand the issue, the regular silicone caulks release acetic acid when curing, while some others release methanol.

Why would you not want to use a RTV capable of handling higher temperatures to seal up the fins--like 3M Fire Barrier Silicone Sealant (releases methanol)?
 
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