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Old August 14th 08, 04:46 PM posted to rec.aviation.homebuilt
Lou
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Posts: 403
Default Are washers necessary?

On Aug 13, 11:03 pm, Orval Fairbairn
wrote:
In article
,
Orval Fairbairn wrote:



In article
,
Lou wrote:


I'm building a wood and fabric plane that uses plenty of aluminum
fittings and
hinges. If I have an aluminum block on one side of a spar made of wood
and the aluminum hinge on the other, with a bolt going through, is
there
any reason for washers? It's not that I wouldn't use them, but it
helps when
ordering the correct size bolt. The plans don't mention washers but
the plans
don't call for a few items that seem to me to be necessary.
Lou


Good practice in wood structures calls for a sleeve through the wood
(epoxied into place), slightly shorter than the thickness of the wood,
and large-diameter washers on each side, to distribute the compression
loads from the bolts. It doesn't mater if you have a block or a washer,
as long as there is a means of distributing the loads on the wood.


I forgot to mention sealing the bolt, to protect it and the sleeve from
invading moisture.



I hate to show my ignorance, but it won't be the first time,
What would you seal the bolt and sleeve with?
Silicone?
Lou