Companionway Washboard Grooves

[P69]

Another project done.  This time, it's the companionway hatch track/groove.  This is an example of project creep.  It started with the idea to replace the teak strip on the exterior of the companionway because 1) I don't like exterior wood and 2) it's easily removable by any thief. My then-solution was  a piece of 3/8" stainless steel flat bar as a drop-in replacement. However this led to the dilemma of how to secure it. Fasteners from the exterior didn't seem very secure, double-nutted on interior seemed ok, but those are tacky double-nuts on the inside that my head might smack into. I still had to figure out how to attach a grab rail. 

So, next was two plates, exterior and interior. . . . Then why not connect them and have double-groove for whatever reason (jail bars and a screen, double washboards to keep waves out, insulate washboard. . . creep... creep... creep, how do I securely fasten the grab rails so they don't rip off when pull on them with my weight?

I finally came up with a solution that provide for no exterior wood, no fasteners on the outside, clean and secure installation of the grab rails and double grooves and it doesn't cost two arms and a foot (< $ 150 in raw material.

First step was to make a temporary washboard because it would be a few weeks to completion. I made a cardboard cutout of the rough opening with a 3" overlap on each side, then threw a layer of CSM with polyester resin, reinforced with CSM strips to prevent cardboard from warping in the sun and when poly cures.

Then I removed the exterior teak and used Fein tool to cut out the molded-in washboard grooves.  If anyone is interested, the interior liner and cockpit are separate pieces and there is a large void underneath the teak threshold.  The companionway ladder brackets are fastedend with wood screws into  2 x 4 block that is sandwiched between liner and cockpit.  The exterior teak is fastened with stainless #10 or #12 wood screws into 2x4 backing  sandwiched between liner and cockpit.  That is why there is a pop-out in the fiberglass liner on the port side. That is to accommodate the 2x4 that runs most of the height of companionway opening.

Once the companionway groove/tongue/track was curt away, I filled and glassed the gaping holes (two vertical and one horizontal). Note in the pictures that the threshold is gelcoated fiberglass. I will leave this and apply nonskid when I reapply nonskid to the deck.  It's also sloped so water drains outboard.

Once companionway was cleaned up, I made a cardboard mockup of the final product, then ordered the metal. Sorry I don't have pictures of the reconstruction of the fiberglass companionway.  I was in too much of a rush to get this job finished before I got hit with several days of rain or a hurricane.

It's kinda scary cutting the boat up without a plan from start to finish.  I couldn't make an accurate cardboard mock up until I removed the teak and groove, then filled in with fiberglass.

Once metal arrived, polished it because polishing stainless after welding is nearly impossible.  Stainless steel is really a PIA to work with. It's a great metal for some applications, but damn, polishing it is take so much effort and it has to be polished to remain "stainless". I don't know which other metal would work for this.  Maybe aluminum but I can only stick weld and that doesn't work with aluminum. I polish with 4 1/2" grinder with 24 grit disk (sanding disk made for metal)to remove the mill scale and pitting, then hand sand from 60 grit down to 2000 grit, finished of with the buffing wheel.  have to be very careful with the grinder to avoid circular grooves.  Grits 320 to 2000 are wet-sanded.

Anyway, once polished, I cut out the rough shapes an tack-welded them together a few pieces at a time to make sure they fit and didn't warp too much. Nothing is square, it all has to be fitted and the two sides are slightly different. 

This whole assembly is fastened with three 5/16" flat head machine screws that are countersunk on the interior, that's it. And the things don't budge.  After I fiberglassed the companionway sides to close the gaps, I spotted the bolt holes and used a 1" hole saw to cut through the interior liner, but not into 2x4 blocking.  I then ran a 1/2" drill down int the center of this hole into the 2x4.  Next was a 3/8" drill bit run at several angles to expand the hole in the 2x4 to form an anchor for the epoxy back fill.  I wanted the back-fill to be larger in the interior the epoxy would be firmly anchored, not just a cylindrical hole, more of a inverted funnel hole. 

After back-fill of all six holes, I put the metal in place and marked where to drill and tap into the epoxy.  Tapped hole is about 1.25" deep. Once it all fit and holes countersunk, I welded the grab rail in place, then polished the welds (well, sanded from 60 grit to 2000 grid, then buffing wheel. Last was the citric acid bath to passivate the whole contraption.

Tools used were 4 1/2" angle grinder with cut off disks and sanding disk to cut and polish the stainless steel, a die grinder with carbide burrs, and a file. Pretty basic tools, but I get by with them. Of course welder and drill press, I don't know how people can drill stainless without a drill press.

Attached are a few pictures and the rest are in the following link.


http://bodylens.com/Gallery/thumbnails.php?album=57

[S/V AMITY]

Looks good!  Its interesting what you learn about the construction of the boat when you start taking things apart. 

[jpendoley]

I like it!  Much stronger than the stock washboard tracks.  Another design I may have to replicate-by the time I am done our boats may be indistinguishable.  The fuel tank design you shared is working out flawlessly and I'm getting ready to build the shower sump idea you shared. Love this forum!

[P69]

I don't have any diagrams of these pieces, this project was done with just a cardboard mock-up of one side.

Here is the exact materials list I used for the metal purchase
Part:  thickness x width x length x quantity

Exterior plate:   0.25"   2.5"   24"   2 pcs
guide face:   0.1875"   2.5"   24"   2 pcs
Interior plate:   0.1875"   3"   24"   2 pcs
Rail Guides:    0.125"   0.75"   24"   2pcs

Exterior Plate: The plate that is on the outside, replaces the teak
Guide face. The plate that spans the companionway opening. The 3/16" rail guides are welded to this
Interior Plate: This is the interior plate to which I welded the grab rail
Rail guides:  These are the thin strips that form the washboard channels.

The return plate that points forward (at the top of each piece), like a flag, is the cutoff of the interior plate where the grab bar is welded.

I uploaded some pictures of the parts lying on the table so you can see the cross-section and pictures of the companionway without the rails.

That flag is for a future latch that prevent the companionway hatch from opening. Right now, there is no mechanism on the inside to keep that hatch closed.

Here is the supplier for the SS.  Free shipping, but you have to send him the materials list and specify 316L (as opposed to 316) because the few items he has listed don't match what you need.
https://www.ebay.com/str/bluemetalsales

One thing to note is that nothing is square or plumb, so it is important to make a mock up before you cut the metal and put a couple of small tack welds to the larger plates to dry fit them.

Uploaded pictures: http://bodylens.com/Gallery/thumbnails.php?album=57