Is Duralac up to the job?

[cjepearson]

I have had a s/s plate made which fits around the mast foot, under the mast itself. This plate is fitted with holes to allow me to shackle on turning blocks so I can lead lines back to the cockpit. The mast and deck mounted mast foot are aluminium, and the s/s plate isn't. My question is...will a good slathering of Duralac suffice to provide insulation, or do you think it will be forced out by the weight of the mast, sails and rigging. Can anyone think of a good material to make a pair of gaskets,perhaps.
Cheers

 

[thalassa]

Made one ages ago from of a piece of PVC cloth "Duraskin". PVC on a polyester weave base. Thin and tearproof.

 

[Poignard]

My alloy mast rests in a galvanised mild steel mast step [a sort of reinforced box] box bolted onto the coachroof. Ten years ago, when I had a new mast step made, I pinched a nylon chopping board from the kitechen and cut it down to fit in the base of the box. The mast rests on that and it has given no problems at all.

 

[damo]

I am also a great believer in the powers of chopping boards for a variety of tasks: galvanic insulation, fairing pads, mackerel paravane etc /forums/images/graemlins/smile.gif

 

[FullCircle]

Totally agree with the chaps, gasket from polyethylene (soft feel chopping board) will do, but make it thinnish, as it will squash under the weight of the mast and the tension of the rigging.

I would always advise the use of Duralac as the protective of choice between S/S and Alloy masts. All my pole fittings etc are coated in it before rivetting.

 

[AndrewB]

Duralac definitely won't work here. I lost the bottom couple of inches of a mast resting on an s/s plate to electrolytic damage. Since then like Thalassa I have fitted a gasket cut out of PVC - no further problems over the last 12 years.

 

[Strathglass]

When I fitted the alloy mast step to the stainless plate on the floors over the keel I insulated it with a thin sheet of lexan. (I have a keel stepped mast)

This isolates the alloy mast and alloy mast step from the stainless plate below them.

I always use duralec when I am forced to use stainless bolts on aluminium.

I also use self adhesive foam between any stainless fittings and the mast.

I was using Duralec this morning when fitting the spreaders onto the alloy spreader mounting bars on the mast Using stainless bolts.

I am a bit woried because my tube of Duralec is almost finished. I had been under the impression that it would last for ever.

Iain

 

[CPD]

Having just used a dollop or two of Duralac, I would definately think you would need something more robust in the application you are talking about.

 

[Boathook]

I read somewhere that the polyethelyne milk bottles are good for insulation as well. I also think that I have used them on board for this purpose but can't remember where !!