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BARREL NUTS
Posted: Sep 21st, '07, 08:36
by Ted_R
Putting engines back in a Cruisers Inc 32? Outboard engine mount bolt holes are enlarged (wallowed out)from years of lag screws not being tight.
The engine beds are good, and have been re-glassed, but they glassed over the bolt holes without doing anything about the bolt holes. I'm thinking best way to fix is to use bolts with barrel nuts in holes transversly drilled in the beds at 3-4" below the mount, install the bolts, then pour in epoxy to fill in around the bolts. Any thoughts/ suggestions? Capt Pat?, Bruce?
TIA
Ted
Posted: Sep 21st, '07, 09:45
by CaptPatrick
Ted,
If you're saying what I think you are, then it'll be a good way to go... See: The Tips Section on
Hardware mounting in Composites, (same holds true for mounting in wood).
Br,
Patrick
Posted: Sep 21st, '07, 22:54
by Ted_R
CapT Pat: Thanks for the link.Close, but on the drwg of the engine mount repair, use longer bolts, drill a appropriate size hole thru the eng bed at a distance from the top of the bed that is about 3/4" less than the length of the bolt, so that when the bolt is inserted, the threads are visible in the hole drilled thru the bed. Retract the bolt enough to slide in the "barrel nut" and tighten it down. Wish I had a picture that I could post, for it would be truly worth "a thousand words"!!!!
Posted: Sep 22nd, '07, 07:22
by CaptPatrick
Ted,
I'm with you now... That will work, although I'm not sure you'd gain much more strength than if you just over drill the holes, fill them with high density epoxy, re-drill, and tap the cured epoxy for the bolt size. The advantages would be that the bolt will now have tooth engagement throughout the length of the bolt & no water could ever get into the to contact the wood.
Epoxy can be filled, (thickened), with just about any dry powdered or granulated substance. A drilled & tapped 2" column of epoxy that has been thickened with steel filings, aluminum filings, or milled fiberglass will likely be stronger than the standard nut for the bolt if it's trapped inside of a form, such as your engine bed...
The type of barrel nut you're looking for should be made of solid steel, (wall thickness of either tubing or pipe is really too thin for maximum tooth engagement). Might be easier to build your own nuts using 3/8"x1" flat bar stock. Figure your spacings, drill, tap, & cut the pieces if you still want to use your technique.
Br,
Patrick