Bedding a mast band on Ngatira.

[Steveh]

I have a new cast bronze mast band to fit to a newly shaped oregon mast. The band is in 2 halves and a snug fit. It is a single band as opposed to 2 bands and a slide for a goose neck fitting. There are 6 cleats screwed to the band with about 1/2" of the stud protruding inside the band. I propose to use these protrusions to stop the band spinning rather than screws.

Traditionally I think leather was used and maybe some white lead/putty paste to bed it but feel there is not enough space for leather, also it would stay wet for longer and perhaps promote rot. This no doubt is why the white lead was used.

With no white lead being available here in New Zealand I was thinking of bedding with an epoxy of sorts but don't feel completely comfortable using this or use red lead mixed with putty. Alternatively I have the use of some 'Dolphinite'

Any thoughts would be appreciated.

[PeterSibley]

What ever it is a fungicidal compound would be best ? I'd suggest red lead ,the goop from an old can and the least putty possible .How does that sound ?

[Thorne]

Don't think that bedding in epoxy will work, as any flexion might cause it to crack. You could possibly coat the mast area with epoxy, and make the dimples for the fasteners slightly oversize and then fill with thickened epoxy. But I suspect that you'll still want to bed the band in Dolphinite mixed with red or white lead. Let's see what the more experienced folks say...

[John B]

All my metal mast bands , fittings , dinghy keel rub strips etc are bedded in epoxy along with microfibres and a colour. It makes a perfect fit , they're easy to remove by heating the metal and when you refit them, then you put them together with some mastic or the like for a perfect fit plus sealant.

[john welsford]

John I miss red lead and white lead paste as much as anyone, and have been trying all sorts of things to see what will work as a substitute.
One thing that I have used with success when bedding bronze against wood is a bituminous paint with a fungicide in the mix that is used for sealing hollowstone concrete blocks against moisture ingress. The one I have is "Flintcoat" but what I have is at least 30 years old and I am not sure if that brand is still around.
We found something similar for Charlies "Resolution" when we fitted the keel, brushed on four coats to build up the thickness required and it seemed to be effective.

John W


I have a new cast bronze mast band to fit to a newly shaped oregon mast. The band is in 2 halves and a snug fit. It is a single band as opposed to 2 bands and a slide for a goose neck fitting. There are 6 cleats screwed to the band with about 1/2" of the stud protruding inside the band. I propose to use these protrusions to stop the band spinning rather than screws.

Traditionally I think leather was used and maybe some white lead/putty paste to bed it but feel there is not enough space for leather, also it would stay wet for longer and perhaps promote rot. This no doubt is why the white lead was used.

With no white lead being available here in New Zealand I was thinking of bedding with an epoxy of sorts but don't feel completely comfortable using this or use red lead mixed with putty. Alternatively I have the use of some 'Dolphinite'

Any thoughts would be appreciated.

[Vinny&Shawn]

You can get red lead powder,from any company that sell chemicals for fireworks,it is inexpensive and shipping is not to bad either.
I think Thorne has a good solution,but it seams as though the I/2" protrusions would promote weak spots and invite water in. Of course anything that is bedded in should always be inspected yearly. Proper maintenance is the answer to averting any problems. My mast band is two bands and just bedded in varnish,but dolphanite seams like a better idea.

[PeterSibley]

John I miss red lead and white lead paste as much as anyone, and have been trying all sorts of things to see what will work as a substitute.
One thing that I have used with success when bedding bronze against wood is a bituminous paint with a fungicide in the mix that is used for sealing hollowstone concrete blocks against moisture ingress. The one I have is "Flintcoat" but what I have is at least 30 years old and I am not sure if that brand is still around.
We found something similar for Charlies "Resolution" when we fitted the keel, brushed on four coats to build up the thickness required and it seemed to be effective.

John W

I've been thinking about a mixture of non hardening windscreen sealant and copper oxychloride ( a garden fungicide) as a bedding compound .Copper seems as good fungicide as lead and is readily available in agricultural supplies quite cheaply.
We can't get get Dolphinite in Australia .

[Don Kurylko]

One of the big advantages of bedding in Epoxy as John B suggests is that you can completely avoid crushing the fibers of the mast as you would if you just bolted the mast band directly to the spar. Leather and metal collars help, but you still need to crank down on the bolts to get a tight fit. With thickened Epoxy, all you need to do is snug up the bolts just enough to keep the bands in place until the resin cures. Then you have a perfect fit without doing any damage to the spar.

Seldom do you get a perfectly round spar or perfectly matching metal fitting, and you can be certain that only the high spots on each will actually come in contact with each other, if you just bolt them in place. Epoxy, on the other hand, will fill the voids and actually provide a perfect mating surface over every square millimeter of the fitting and spar. Furthermore, because the original bearing surfaces are not a perfect match, once epoxied they will have far less tendency to shift or rotate. The grip will be extremely tenacious, even without considering the gluing properties of Epoxy.

If there are studs involved, these are best let into oversized holes and also filled with thickened Epoxy. The Googe Brothers have done extensive testing of these types of applications and they have found that Epoxy has only increased the holding properties and strength of the fittings without compromising the wooden substructure in any appreciable way - even going so far as gluing the bolts of highly stressed fin keels directly to wooden keels.

But one thing that I would advocate is the use of two bands for the gooseneck - one upper and one lower. This will reduce the stresses on the mast and fittings considerably and almost completely mitigate any possibilities of failure or damage to the spar under load. I would never consider a single band except on small boats under 20’ or so.

[PeterSibley]

I should have said that my mast will be a solid stick and I doubt epoxy would deal with the movement , a flexible no hardening bedding compound sounds good .

[Steveh]

Two schools of thought going on here. While using epoxy it does give the ultimate fit but with movement could let in moisture. I bedded the mast step with epoxy but painted red lead to the timber first. The perfect fir and fugal protected.

Vinny&shawn have hit the nail on the head though. It's all about maintenance. Not that I want to be taking the bands off each year but checking would be good.

Will only be using two of the cleat lugs into the mast. Fitting tomorrow so will sleep on it.

[Steveh]

Well I went with two options. We bedded the band with epoxy but well thickened with micro balloons and a bit of red ocher on top of the varnished spar. The port and starboard cleats are run through the band and threaded into the mast about 12mm (1/2") These are bedded with dolphinite and a drop of locktight. The remaining cleats are flush to the inside of the band and bedded also with dolphinite and locktight.

Launch day tomorrow.

http://farm3.static.flickr.com/2543/4191729181_9bae952f33_o.jpg

Pin rail yet to be fitted, and boom.
http://farm3.static.flickr.com/2786/4192491104_9f1909bf01_o.jpg

http://farm3.static.flickr.com/2592/4191729271_346d05e35d_o.jpg

[snow(Alan H)]

Holy hell Steve - do not let Harold see the shine on that bronze !! See you in the morning.
Houghty

[Nanoose]

OK...I have now experienced a new level of lust. :(

[Lucky Luke]

I've been following the restoration progress thread since the beginning: Now she's DROP DEAD GORGEOUS!!!:)

She will (re!) enter History through the main gate! (hope my direct translation from French is understandable...?).

Can't wait seeing her under full canvas!

Congratulations!