More Mast Step Re-Enforcement Questions

[andyatos]

So, I going to start up the process of re-enforcing my mast step. But I've got some more questions. Here goes.

I'm going to follow Voodoo's process of cutting a precise hole in the deck, doing the work then putting the deck piece back. Here's what I'd like to know.

- How big a hole, in diameter, should I make that's going to give me enough room to get my arm in there and do the work?

- Where exactly should I cut the hole relative the mast step? People talk about ridges of re-enforcement that run under the deck. How do I avoid having to cut through those?

- Voodoo, you created a 6 layers of glass and epoxy sheet as a base to put the piece of the deck you cut out back on. What grade or weight or whatever name it's given of glass did you use? I'll be using West Marine as my source.

- I'd imagine the weave is fairly fine so that you can… bend it to get it through the hole? And that's my next question. Does your 6 sheets with glass and epoxy make the final product just flexible enough to bend it so you can get it through the hole?

- For re-enforcing the mast step, what weight or weave of glass cloth do you use there? And what kind of epoxy resin do you use? Again, West Marine is my best, closest source.

- How far out from the mast step base did you come with your glass onto the floor of the hull? How far up the mast tube did you go with that glass? Did you do just one or two lay ups of glass?

I think that's all the questions I have. For now.

Thanks,

- Andy

 

[Voodoo 158546]

Morning Andy.
Points in turn.
If you can get a deck hatch - one that you might install here - use that as your template just as if you were going to install it. So five mm inside the screw circumference would be your actual cutting line. Then if things go wonky you can always revert to installing the hatch later.

Where ?
Far enough away to glass the top of the tube to the 'roof' ( 50mm ish) but close enough to reach around the base.
Approx 45 deg' off centreline and aft of the socket. Below, waxed ready for taking a gelcoat moulding.
Remember there is a lot of pressure on this deck area once the boat gets going, give the socket a bit of room.

What weight cloth ?
200gsm.
Sheet cloth for the flat panel for the cut out backing,
for the tube itself tape would be easier than cloth sheet to manipulate in here, give a neater finish too. A roll of 50 metres of 200gsm glass tape for epoxy cost around £15 /$25 ?
I use the west system resin too.

The backing plate is about 50mm bigger than the cut out, then trimmed one side to a rectangle to about the same size so as to squeeze in there.

How far out at the base. How far up the tube.
Bottom (to hull ) layer out around 75 mm from the base with following layers creeping inwards approx 15mm a time, holding back with the last two until the tube gets wrapped then those last two over the tube wrap. You gotta really consolidate all these bits of wet cloth, get the bubbles out.
From the top of the doughnut to the deck above and out onto the deck for 50mm, two layers should be ok if your using sheet, if taping I'd go up then down in the opposite trajectory.

 

[Voodoo 158546]

This hatch was installed a fair bit closer (and inline with the socket ) than I'd be happy about. You think, reaching/ running there's not a lot of structure bearing loads abeam of the socket it's just a thin plastic loop/air space. See the dark stripe heading fore n aft ? Reinforced area.

Here you see the reinforcement pad around the socket, I'm not actually sure of its diameter around the socket but it seems to be around 50 mm ish..

 

[jeffers]

Good stuff above, just remember to be far enough away from the centreline of the boat that you do not go through the thicker bit down the middle (I seem to recall that was there on a boat I did a repair/reinforcement on).

 

[Voodoo 158546]

Ahh forgot to add - a small mirror on a bit of bendy wire is so useful for watching what your doing around the back of the tube and where you can't see up on the deck,

Here you see the ply backing pad I glassed in for the cunny/outhaul deck leads... it takes all the hit n miss guess work out the equations.

Here's how far out across the hull. See the partially keyed up areas.
Don't forget to tape up your cut out, to protect your forearms.

 

[jeffers]

I webcam works well too if you are technically minded.....

 

[Voodoo 158546]

I tried utilising the keyhole camera but kept knocking the cable and getting it all sticky just when I needed the drama least. So I reverted to 19th c tech.

 

[andyatos]

Excellent, excellent Voodoo! The fine details are much appreciated.

I'll go through your descriptions and likely return with a few more questions.

- Andy