[Rhodes22-list] Mast step tabernacle attachment/deck repair

[DAVID BERG]

Rhodies,

 

I recently liberated my mast step tabernacle from the deck while (not)
raising the mast. At first I was perplexed that the machine screws pulled
right out. After further review I've learned that this is by design. I've
reviewed the post that I could find related to the repair, and called West
Systems for their take. I'm still left wondering which way to go. I'm
wondering if anyone has anything to add. 

 

I was going to fill the cleaned and chamfered holes with thickened epoxy
(System 105/205), with no toothpicks or wood shavings. Then drill and tap
the semi-cured epoxy for the 1"-20 machine screws. The questions I had
regarding this method were:

 

1)      Why do I need wood shavings or toothpicks? I don't plan to take the
screws out for any reason.

2)      If I let the epoxy set up (but not cure) would I be able to drill
and tap it?

3)      How long would I let it set up before drilling? It seems form my
research that drilling and tapping fully-cured epoxy is very difficult.

4)      If using the epoxy with shavings or toothpicks what is the order and
timing of the re-assembly?

 

After talking to West Systems, I think I'm leaning towards what they said to
do:

 

1)      Clean out any old material 

2)      Oversize the holes to make room for the epoxy between the machine
screws and the existing deck

3)      Chamfer the top of the holes at the deck

4)      Wet out the holes and screws with un-thickened epoxy

5)      Thicken the epoxy with 406 or 410

6)      Fill the holes with thickened epoxy

7)      Set the tabernacle plate and insert the 1"-20 machine screws 

8)      Clean off the excess epoxy that is displaced from inserting the
screws

9)      Tape the screw heads down to prevent the screws lifting from
hydraulic pressure.

10)   Let it cure and go sailing

 

With the solid (non-cored) deck, there should be no need to use any butyl or
sealant. 

 

Looking for any other advice or opinions anyone may have on the topic.

 

David Berg

Blue Loon, Rhodes 22 1996/2003 

Minneapolis

 

 

>From Graham Stewart July 2020

Chris:  If the gelcoat around the holes is mearly broken up a bit you should

be able to remove anything that is loose and fill it with the thickened

epoxy when you fill the holes. Given that the holes are covered with the

mast step anyway, you don't need to worry about the exposed epoxy. Epoxy

exposed to sunlight degrades quickly. I really like the idea of using

slivers of wood in the hole with the epoxy. I wish I had thought to do that.

I would not pack it hard with the wood slivers - maybe 50% wood and the rest

epoxy.

If the screw is inserted into the epoxy I see no reason or benefit from

removing the screws to inspect the holes. That might cause more problems

than it solves. One thing you should note is that screws driven into uncured

epoxy can be very difficult to remove and it is quite easy to strip the head

or even break it off. The wood slivers should help but if the screw is hard

to remove put a soldering iron on the head for a while. That softens the

epoxy and it will come out easily.

 

If this event reoccurs it is likely that the screw will pull out the epoxy

plug since it is much tougher than the core material, Hopefully this does

not happen very often but if it does the fix remains the same. 

 

Graham Stewart

Agile, Rodes 22, 1976

Kingston Ontario