Corban 27l joint compound

[chrisran]

Just wondering if anyone has any experience using this product?
LAS sell it and from what I’ve read in the product info, I think it’s a viable alternative to chromate based compounds for static joint corrosion inhibition on aluminium. I’m building an rv7

[Ian Melville]

That is a new product to me, and reading the spec it would appear to be a good replacement. I do like the fact that it can be cleaned up with a Citrix based cleaner(or MEK), whereas Duralac sticks to everything forever The one downside I can see is that it is non-drying(as is Duralac), and is more spreadable at a temperature as low as 100F. Panels in the sun may reach this even in the UK.

IIRC painters aren't keen on Duralac on panels that present an exterior finish, as they can weep long after the final paint, ruining the finish. I can see Corban 27 being the same. Would be interesting to see where Boeing use it. I suspect for bolts and parts that need to be removed at some point.

Options seem to be limited for fayed and lapped panels.These need to cure but remain slightly flexible. PR-2870 from PPG seems to fit the bill, though I cannot find anywhere to buy it! LAS sell PS870 the older chromate version, so perhaps we need to pressure them to stock it?