2007 at the Hammond Barn

[Richard Farrant]

Originally posted by Bob Carriere
My old dad use to have a small half pint container of some kind of GooH...... smelled like shellac but had a cooper dust mixed.....he said it was used on "hand lapped surfaces" for aircraft engines when no gasket was used.....

Bob,

I use a sealant that was developed by Rolls Royce for their aircraft engines originally, called Wellseal. It is a type of shellac and only needs a very thin coat, then allowed to go off for about 10 mins. when it gets sticky. You set up your shimming first, then strip and apply the sealant between each shim. Experience will tell you how to compensate for it on the shimming, dependant on how many shims are used. If you were using brand new shims, there is often no problem, it is old ones with the odd wrinkle in them, that cause the problems. Re. the remark from your bearing guy about the bolts should pull the shims tight, not always possible if the item has relatively small diameter studs or bolts.