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Re: Paint under bolts

To: tigers@autox.team.net
Subject: Re: Paint under bolts
From: Carmods@aol.com
Date: Mon, 28 Jun 2004 08:45:10 EDT
<<Can anybody speak to the affect of a fresh layer of paint between a 
properly torqued nut?  I've heard some claim that pulverized paint can 
leave the lug nut holding nothing but air.>>
Bob, 

If you are bolting pieces together that have paint under the bolts, nuts or 
washers, the paint will creep out under the high compressive stress and the 
bolt will lose it's torque. Very thin paint is no problem but the thicker the 
paint the greater the problem. In some cases you can see the paint build up 
around the bolt as it squeezes out.

To eliminate the torque loss without removing the paint, just re-torque the 
bolts or nuts periodicity, after assembly until you can see that the bolts or 
nuts will take the torque without turning.  Normally the creep will be finished 
within the first few hours or days unless the paint is unusually thick.

In modern automotive applications, cone shaped washers with very high contact 
stress at the outer circumference are often used to get through the paint 
while it is being torqued.

                                                                              
                      John Logan





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