Mast step lifting

[Tipster1]

I am considering adding a 1/2 to 1" shim under mast step to compensate for former owner's dis-mastng and loss of short section of mast at tabernacle. I'll either be using some plywood or nylon cutting board as a shim.
The mast step seems to be fastened by screws going down below cuddy floor. According to Roger Conrad's book there is some sort of structure under there to receive these screws. What I cannot see is what kind of screws these are. I would like to be prepared with replacements before I start this. Should I use any sort of material in holes when I re-attach mast step?
Mark B
1975 DSII #7303

[jdoorly]

Is the mast base sitting on a stainless "C" channel with holes along the side and a pin through the mast base? If so then it is like my mast base. The five screws through the "C" channel are #10 x 2" flathead and are held by 5/4 plywood (which in my case was thoroughly rotten). The ply was glassed to the cuddy "floor" and backed up by a thick PVC pipe which was sunk into the ply 1/2", and telescoped and sealed into a bigger PVC pipe on the keel. I replaced the ply with a 1"x 3" x 12" piece of maple I had, white oak would be best but anything covered in epoxy should work well, however I have excellent access to the mast support area, having cut away a footwell in the cuddy. I had previously used up to a 4.5" shim under the "C" channel with no problem. Of course the problem would be loosing a stay and the resultant side force felt on the mast base connection, so the smaller the shim... One of my winter projects was adding 6" to the base of the mast by adding a 6" DM284 extrusion and a 12" sleeve (a DM284 with slot cut off) inside that and everything riveted together. Now I feel warm and fuzzy and only have to worry about installing the drain plugs before splashing.

Note: The tangs for the stays was raised 1.5" hence good timing for my dyneema stays project!

[Tipster1]

Thanks for your reply. My mast step is attached by only 2 screws. Are they just long stainless sheet metal type screws?
.
Seems to me, if these are just long sheet metal screws, then removing them, removing mast step, inserting shim (I plan no more than 1") and then replacing screws with additional length and some filler should do the job.

How about some pictures of your cuddy foot-well?

Windsurfers use Dyneema for down-hauling. Stuff is incredibly non stretch. I suspect even stainless wire has a little more give in it. Might that be a downside?

[jdoorly]

Hi Tipster, You have a standard mast base casting. I think below the floor you have the plywood/fiberglass/PVC that I described. I would take both of the screws out testing their grip (i.e. the state of the ply) as it comes out. Replace with longer screws as you described. If the wood is not too bad I would fill the holes with thickened epoxy and redrill new pilot holes. If you have lots of clearance at the partners (the hole in the roof) you may have enough room to make new holes a little forward or aft of the old ones. If the wood is pretty bad I would drill the old holes out with a 3/8" bit or larger, fill with thickened epoxy, then redrill the pilot holes. If the wood is really really bad I would think about an access hole or a footwell and replace the plywood.

Sorry, no pics yet, I keep forgetting! Actually, the cuddy interior is on Rev 2 now. Originally, I cut out a hole in the floor just to get my 2 group 27 batteries down low. I enclosed the batteries and there are pics of that interior in my gallery. Last year I cut out the whole area from aft of the mast to the bulkhead. I laid in some wood frames and covered with 4mm marine ply except for the footwell. I moved the batteries up against the bulkhead. It looks nice but there really isn't enough room for humans in there.

They do have a dyneema based line rated for standing rigging. It is a dyneema cover with a dyneema core. But that's not what I used, I used 1/8" 12 strand single braid (Amsteel Blue). I tried it on my forestay first for a year and a half. Now I have dyneema shrouds as well. Dyneema is known for not stretching, however, under condition of constant load for extended duration dyneema will "creep" (stretch). Since the shrouds see a few hundred pounds for 4-8 hours I expected the stretch and put the line under load over time. My original measurement for shrouds was 195" (I use a Ronstan shroud adjuster instead of turnbuckles). The line stretched 6" before becoming stable. This agrees with the spec's I have seen, i.e. 3%. There are several types of elongation spec's (stretch) and it can get pretty confusing, at least for me.

Dyneema has lousy "hand", can't imagine running rigging using it unless it's as a core with a polyester cover. Mmmmmm, light air sheets...

[Tipster1]

Thank you a whole lot for taking the time to respond in such detail. Now, given much better understanding of anatomy, I fell completely confident in raising my mast step. Only thing to find is suitable shim. Will be cruising dollar stores looking for cutting boards as well as trash picking, a NJ Monday sport.
I just browsed through your gallery. Your imagination is off the chart. I can only begin to imagine what your shop looks like.

[Tipster1]

PS. Once Dyneema has stretched it's 3%, is it stable, so you can trailer sail? What made you decide to use the Ronstan adjusters instead of turnbuckles? To re-rig, did you tie on line yourself or do something more elaborate? I am imagining that this is nice and soft to handle, makes rigging and derigging easier. How's cost, compared with SS prepared in a riggin shop?

Windsurfer's use 6mm Dyneema for down-haul in a 6:1 purchase starting at 5-6' and getting down to total distance of 2-4" so stretch and creep not an issue. We like the idea is that it is strong, flexible (pulleys are usually no more than 2cm, and cleats reliably in a clam cleat.

[jeadstx]

Below the mast section inside the cuddy cabin you have a compression post that goes to the keel.

I put two 6" inspection ports in my cuddy cabin floor to get at things under the cuddy cabin floor. Also I thought it might me a way to store water for on the Texas 200. So far the only thing I've stored down there has been my old original stays and old spreaders as spares.

John

[Tipster1]

Thank you for furthering my knowledge of my boat. I finally spoke to the former owner and what he described was driving into overhead power line slowly, but with enough force to actually break vertical tab on stem head, without damage to screws, base plate, or deck/hull joint. All he needed to do was remove intact machine screws, install replacement stem head and screw back down. It sounds like he had real metal to metal connection. My confidence is restored. Following are some pictures of what happened to tabernacle. He said attachment holes were elongated, so he trimmed the mast a little and re-attached an new tabernacle. Small tab is what broke off stem head!

Only thing left for the moment is install base shim. . I have removed mast step, although, like everything else, one screw was easy, other was frozen, so I had to remove centerboard lift pulleys so I could spin fitting out. Now it's soaking in PB Blaster. Tomorrow, the impact driver. grr.

[TIM WEBB]

In a way, it's a good thing that the vertical portion of the stemhead acted as the "weakest link in the system"! And it shows that your L-bar underneath is probably in good shape. Beats having the deck peel back!

My PO installed a 4" x 5" piece of 1/8" aluminum plate under the step that's held in place with 6 self-tapping screws. The step is bolted to it. Not sure if it was an attempt to raise the step or spread out the load or both or what ... ?

[Tipster1]

Getting ready to install mast step shims made from 3/4" pvc trim I found on a construction site:


Pretty cool, huh? This stuff is rot proof, water proof, UF proof, easy to work with (and free!)

Tell me more about Dyneema shrouds. Is this a DIY project?

[jdoorly]

Hi Tipster, Dyneema stays work for me because I need new rigging but can't afford it nor can I maintain the expensive fittings for changing wire cable length . I already have plenty of dyneema so it's free and it's easy to splice so I can maintain it. I like working on my boat just as much as sailing her so they won't go un-inspected and I still have enough dyneema left over so I can replace or reinforce anything that starts to appear in need. It saves some weight aloft being stronger and lighter than steel. It's abrasion resistant but I think wire cable might still the win the knife or scissor tests. It's UV resistant but I have trouble believing it will last like wire cable.

So, I thought it through and I'm willing to try it, but since it's only been around a relatively short while I won't suggest anyone else try it, indeed I suggest they stay away from it for now. I'm still ironing out kinks- tomorrow will only be my second sail with all 3 stays synthetic!

[Tipster1]

How do you splice that stuff? The material I have seen is a core and a jacket.

[jdoorly]

Here is the method I use: http://www.keepitsoaring.com/LKSC/Downloads/dyneema%252Fspectra-splicing-manual.pdf (See page 8 for eye splice)
except I haven't found a needle for the knitting need, the 6.5" 50::1 (50 x 1/8" thick 12 strand singlebraid dyneema) bury seems to fit scrunched-up on my 1/4" stainless Selma fid, which always works perfectly, my 1/4" aluminum Samson fid sucks and doesn't get used! Also, the brass fid I made before I found the Selma, which works better than the Samson, sucks and doesn't get used). Selma- better splicing through fidding around...

This PDF doesn't call it as such but they are making a Brummel splice, as the 2 parts are mirror images and lock on each other before the bury begins. Of course there are more complicated ways of doing this but my mind begins to melt and it all turns into a Mobius strips when they try to reduce stresses on inside out holes and such...

Don't get me started on splicing doublebraid

[Tipster1]

Mast step shim installed. Lee helm corrected!