On Tue, 24 Apr 2012 11:55:25 -0400, "Flying Pig"
wrote:

If you've been paying attention, you know I've dropped my rudder and have
been removing prior attempts to epoxy pits in the shaft - done in a
convoluted, upside-down manner, inside the boat - which turned out badly.
With the rudder out, I have access to it conveniently, to do it up right
(well, as best as possible in that it can't be sent off for grinding,
rewelding, and machining to round again).

I believe I have all the prior epoxy out. Some of the pits have tunnels up
or down, too, which, as I worked them out with the pick, displayed remnants
of prior packing material. Not so good. The good news is that nearly
everywhere I managed to pick off shows very bright under the old epoxy, so
it's clean (or will be when I use a brush and acetone to remove all solubles
which may be hiding on the surface, and which would impede bonding).

The area covered by the packing gland has minimal reduction in diameter -
mostly 2-5, and at worst, ~8 thousandths of an inch (out of 2"). However,
I'd like not to have even that, if I can avoid it...

===

Well everyone else has had a shot at this so I'll dip my oar in the
water also. Rick is on the right track with his mold approach but
I'd do it differently. I'd buy a sheet of heavy duty mylar which is
available at any art supply store or sailmaker. Next I'd coat one
side of the mylar with wax or mold release. After filling the pits
with Devcon/epoxy/Colloidal Silica or whatever, I'd wrap the shaft
tightly with the mylar (wax side down of course) and try to squeeze
out any excess epoxy as I wrapped. Leave the mylar on until cured by
wrapping it with masking tape or some such. If done properly, this
will minimize the high spots and the amount of sanding to be done.

The sanding should be done with long strips of emery cloth or wet and
dry sandpaper, using them like a shoe shine cloth wrapped around the
shaft at about 180 degrees. Change the angle frequently to avoid
making an oval shape. I have successfully dressed the shafts on
anchor windlasses in this way after they've become dinged/distorted.

On Tue, 24 Apr 2012 21:28:47 -0400, Wayne.B
wrote:

Well everyone else has had a shot at this so I'll dip my oar in the
water also. Rick is on the right track with his mold approach but
I'd do it differently. I'd buy a sheet of heavy duty mylar which is
available at any art supply store or sailmaker. Next I'd coat one
side of the mylar with wax or mold release. After filling the pits
with Devcon/epoxy/Colloidal Silica or whatever, I'd wrap the shaft
tightly with the mylar (wax side down of course) and try to squeeze
out any excess epoxy as I wrapped. Leave the mylar on until cured by
wrapping it with masking tape or some such. If done properly, this
will minimize the high spots and the amount of sanding to be done.

The sanding should be done with long strips of emery cloth or wet and
dry sandpaper, using them like a shoe shine cloth wrapped around the
shaft at about 180 degrees. Change the angle frequently to avoid
making an oval shape. I have successfully dressed the shafts on
anchor windlasses in this way after they've become dinged/distorted.

Good thinking, Wayne. May I add a "mod" or two?

Your post triggered a memory. Saran wrap makes a great "mold release",
actually better than mold wax. It could be wrapped around the shaft
first.

Heavy duty mylar sounds good, as well as thin metal, aluminum or maybe
better stainless. Pre-formed by working around the shaft before the
epoxy.

How about however many engine piston ring compressors needed to "wrap"
the mylar/metal sheeting? You know, those things that squeeze the
rings down on a piston so you can slide it into the cylinder?

This method will leave a slight ridge where the mylar/metal overlap,
but should be a problem.

I agree 100% with the "shoe shine cloth" method of finishing.

Rick

On Wed, 25 Apr 2012 06:23:53 -0500, Rick Morel
wrote:

Your post triggered a memory. Saran wrap makes a great "mold release",
actually better than mold wax. It could be wrapped around the shaft
first.

===

I have used saran wrap and also light weight plastic sheeting. They
both "release" well but tend to leave wrinkles in the finish. Heavy
mylar sheet like pattern making material will not.

On Wed, 25 Apr 2012 07:55:17 -0400, Wayne.B
wrote:

On Wed, 25 Apr 2012 06:23:53 -0500, Rick Morel
wrote:

Your post triggered a memory. Saran wrap makes a great "mold release",
actually better than mold wax. It could be wrapped around the shaft
first.

===

I have used saran wrap and also light weight plastic sheeting. They
both "release" well but tend to leave wrinkles in the finish. Heavy
mylar sheet like pattern making material will not.

Good point!

Rick

On Tue, 24 Apr 2012 19:26:24 -0400, WaIIy wrote:

On Tue, 24 Apr 2012 11:55:25 -0400, "Flying Pig"
wrote:


So, back to all my begs in one ask-it, are there any better ideas? And, if
this idea is da bomb, what's the best way to manipulate this sanding shoe to
achieve the best results, in your collective opinion?

L8R, y'all

Skip, working on the boat

Are you SURE you trust this epoxy?

What's going to happen when the stainless corrodes and starts
popping the epoxy off?

It's not too late to stand back and rethink this thing.


I haven't paid much attention to this, but dressing a pitted shaft is
something I'd avoid if the cost for a new shaft isn't outrageous.
And if I did dress it, a pro would do it.
They have flame metal spray, welding build-up, etc for shaft
restoring,
By the time you figure the material/labor/doubt cost of DIY, it
might be better to buy a new shaft or have a pro rebuild the old one
with proven techniques.

--
Vic