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Releasing a sheered off bolt by welding

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What is the issue?
Bolts and nuts, like most every fastening, have a tendency to seize up on boats due to the challenging sea going environment. Apply just a touch too much pressure and the heads can sheer off leaving a seized and often inaccessible bolt shaft.

Why address this?
A sheered off bolt can halt a project, cause frustration and cost money.

How to address this?
Weld in a smaller bolt to the shaft as presented in figure 1.
This approach is almost guaranteed to remove even the most stubborn bolt.
The bulk of the work is carried out by the welding process itself. The heating action of the weld breaks the molecular bond fixing the bolt or screw threads. In addition to this the heating and cooling action fractionally expands the metals at different rates aiding separation. The light bolt is to support an adjustable wrench working the bolt out. Here are the steps.
1/ Find a smaller short but solid bolt.
2/ File or grind the sheered off bolt until it is flat.
3/ Locate and mark the sheered off bolt's center point with a center-punch.
4/ Drilling in a hole that your selected bolt comfortable sits in. This need not be very deep. A three to four millimetre seat is perfectly adequate.
5/ Weld the bolt with the lightest rod that will stick to the shaft.
6/ Cool for five to ten minutes then get a spanner or adjustable wrench on the smaller bolt head.
5/ Nudge it back and forth with the wrench to work it free
7/ Turn the bolt out when it frees up.

With thanks to:
Bernard Harpur, Co. Wexford, Ireland

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