Crazy mast step hole fitting Idea

[davidpm]

I've got the wood plug epoxied to the 2" alum mast.

The mast step is in.

My old carpenter ways would have me use a chisel and notch the mast step till it fit.

Now that I'm trying to do things the epoxy way would this work.

Bore 2 1/8" hole. in mast step.

Wrap mast plug with a few layers of masking tape.

Cover with saran wrap.

Put thickend epoxy in oversized mast step hole.

press in mast and level epoxy.

After epoxy is hard remove wrapping on mast and presto a perfect fit.

Will this work?

[PeterP]

Sounds reasonable to me except your epoxy will chip like crazy. Every time you drop the mast on the edge you will flake some off. That stuff IS brittle. Nevertheless, I am giving you an A for inventive thinking . PeterP

[davidpm]

I've uses builders plastic as a release film but never saran wrap.

It may too thin.

[wkisting]

David,

Some kinds of saran wrap will NOT release from epoxy. I learned that when building a kayak long ago. Stick with the thicker mil builder's plastic, preferably 4 - 6 mil. Thinner stuff may stick, or will, at least, tear annoyingly into little bits as you try to pull it free of an epoxied surface, causing you to spend lots of frustrating time scratching at the tattered pieces with your fingernail and cursing the folks at Saran Wrap Industries. 

[PeterP]

David, here's another way of doing this. Take your wooden mast plug and clamp it in a say Jorgensen clamp. Mark the two flats you need to cut of. If you have a band saw run the plug through it. The Jorg clamp will keep everything lined up right. Pick up the two wedge shaped chips & sand out the saw marks - sand out the flats on the plug. Don't be afraid to over sand as you'll be building it with epoxy later on. Apply release agent of your choice to the plug. Coat backside of chips with epoxy and insert all of it into the mast step hole. Hopefully when it sets up your release will release as planned and the plug will pull out. Sand the mast step top flush, sand to fit. If you don't  have a band saw-hand saw will do in a pinch. As a safety -in case the epoxy  ever  lets go -drive a couple of small nails/screws through the chips into the step. PeterP

[markja]

After trying to hack out a hole with flats in my mast step, I gave up and did what Peter described. bore a round hole and filled in with cutoffs from the mast plug.

[Gordy Hill]

I had problems with a wooden mast plug.

In the Great Race it swelled. First, I had trouble unstepping the mast to pass under a bridge. Then, later on while sailing I noticed the marks on the main mast indicated it was sitting higher by about 1 1/2 inches. Just as I got forward (It was very windy and rough) the mast broke free from the step and tipped alarmingly. I caught it just in time and managed to reset it fully into the step.

Later, I decided to replace it. I used a one inch thick piece of plastic, polypropylene I think. I used a 2 1/2 inch hole saw and cut until the pilot bit just showed through. Then I turned it over and used a slightly larger hole saw starting the pilot bit in the hole. The resulting plug was exactly the outside diameter of the mast for 1/2 inch and exactly the inside diameter for about 1/2 inch. I epoxied it to the mast and it never came loose. Of course it could be because it fit so well. I then rounded the edges and it worked beautifully and allowed the mast to rotate easily.

With a thicker piece of plastic you could have enough to trim the bottom differently.

[davidpm]

Apply release agent of your choice to the plug.

Do you use any release other than builders plastic?

Unfortunatly I belt sanded the flats so i have no chips.

[davidpm]

Could you use Spartite instead?  It's what my big boat's mast uses.  Works a treat at the partners.

http://www.spartite.com/spartite_techspecs.aspx

Looks like good stuff but for a different purpose. The spartite is to form a water tight seal.

In this case I just need a reasonably accurately shaped hole.

Their FAQ mentioned using petrolum jelly for a release which is an interresting tip.