Tuesday, March 27, 2012

Building A Fiberglass Hatch

Although we have put many dollars and hours of effort into the old Mercedes, Sarah and I have decided that we need better worldwide parts support and modern compact performance that the Old Mercedes diesel engine can't offer.  Enter our newly rebuilt, 0 hours, Japanese-built Yanmar diesel.  Half the weight, half the size, less a cylinder, and still 80% the power of the old beast.  Parts are cheap and readily available around the world.

Since a leaking flush-mount hatch led to the damage on the Mercedes, I decided to make a new raised-lip style one from scratch.  The lip will be glued into the hole remaining from the old flush hatch, and the new hatch will fit properly over.

Here is the initial fiberglass cloth trimming.  The mold is simply 1/2" MDF covered in packing tape, then taped to glass, and then the whole assembly is waxed with mold release.  Corners are filled with modeling clay and rounded with a popsicle stick to provide a smooth surface with rounded corners after the wax has been polished.

Tools of the trade: Polyester Resin, MEKP catalyst, respirator, rollers and a Bondo squeegee to remove bubbles, cheap natural bristle paint brushes and plastic pails for mixing not shown.  Acetone for clean up.

Learning the hard way: Lay up of the hatch lip (version 2.0).  The first one was done as a reverse lay up for ease of bending the glass mat, but and the sealing surface was unacceptable, so I reversed the mold and made this one.  Better dimensions and surfaces, but it was difficult to keep it in the tight inner corner as it cured...  difficult, but not impossible.

Here is the hatch the next day, fresh from the mold.  Notice modeling clay around the corners, unfinished edges, and the 1/2" core material in the middle.

Smooth as glass (face) ...  and packing tape (edges) ...  and modeling clay (corners)

Fiberglass cuts with good plywood circular saw or table saw blades, but I used a small lightweight tile circular saw to cut the edge to the mold line.  Then a bit of cleanup with a small air grinder and some hand sanding.  There are some half bb or smaller pits in the surface that will be faired and filled with Bondo before final sanding and white polyurethane topsides yacht paint from Interlux, and then re-laying the teak from our old hatch on top using just Lifecaulk or 3m 200 (no screws).  The core is a plastic honeycomb backed with flocks so the resin binds with the outside surface, but the core remains air-tight, hollow and resin free.

I stopped by Sarah's work to show off the finished hatch.

The hatch will be plenty large for our new engine to come in from the top instead of through the engine doors into the cabin and then up through the companionway...  even though the hatch is the exact same size as the old one...

Soon the shop will be unavailable and Sarah will be quitting her job in 30 days.  The plan is to have the motor in and be headed to a haul out right about the same time.  These next 30 days will be full of wiring, solar panel installation, engine room painting, and general rebuild on the aft end of the boat!  At haul out we will be able to pressure wash and paint the bilge, hull, and decks, seal the stanchions and windows, and ready the boat for the new rig.  We'll tell you about it soon!  - AJ


  1. Ahoy from a fellow Arkansan (I live in Little Rock). I've been following you two through your highs and lows of this journey you've started together and and I'm excited to hear about the progress you've made with your boat. Congrats on the new engine; you made a valiant attempt of getting the old one working but I think you're better off with the Yanmar.

    You both continuously talk about the amount of things that you need to get done. Is there any way you could write the stuff down (maybe make it a page on it's own), then mark off the items you get finished... that way we could have some way to track your progress? If that is not really possible I totally understand, but I've always wondered what people go through to prep a boat for a life-long cruise. Plus there is always the possibility a sponsor might see it and help you out along the way.

    Anyways, safe sailing and I look forward to more of your adventures.

  2. Just for you, I made a “Checklist to Launch” page that can now be found at the top of the Blog. I’ll keep adding to it/changing it as things come. Thanks for your interest and comments!

  3. Hello from Frankfurt, AJ>
    good job with that hatch!
    clever job.
    since I have the same model Luders 36 (with a miserable perkins 4-108 that needs to be replaced), I'm wondering if you are going to also have to replace the coupling and the shaft?
    also, how did you get in there to disconnect the engine from the shaft? on my boat I have to lay upside down in the starboard lazarette to reach the stuffing box!
    keep up the good work!

  4. Hi again>
    AJ, I had another question/request>
    it's about the original Cheoy Lee bronze, bilge pump cover that you guys mentioned awhile back.
    I have the original cover on my boat, but there's nothing underneath it. I bought a Whale Gusher pump and I wanted to rig it up so that I could attach the handle through this bilge pump access hatch>
    how does the plumbing on yours look? My electric bilge pump discharge exits through a thru-hull in the transom. Do you have a separate thru-hull fitting for the manual pump discharge?
    Thanks again> db//

  5. We used a big whale gusher manual pump as our head discharge, it works really well. We love the old original draw pump as it really pours water and can not be clogged. It exits at a thru hull on the side near the waterline: about 24" hose run. Plus the valves and disc can be made of leather by hand. I would recommend it. Here is an original one on ebay:
    just unthread that hideous pipe and elbow and replace with a threaded nipple

  6. The coupling will have to be replaced, not sure about the shaft yet. Probably though. When we drop it in we will find out for sure. Hopefully will do that by next week. if it does not fit we will replace it on the hard when we haul out.

  7. Hello AJ & Sarah: As usual, Great Blog.

    I offer a few unsolicited comments …..you’ll get that from cruisers! Something about Opinions are like As$#@&s. Anyway…………..

    Very impressive work on the hatch. AJ, you can thank your Dad for nurturing a valuable skill in you early. Your design and glass-work appears to be top-notch. Even in the most remote anchorages, you will be able to parlay that skill into work/$$. Most cruisers can cobble something together with some West System, but seldom is it functional AND professional looking.

    Personally, I would not have been in such a hurry to ditch the Mercedes engine. Yes, the Yanmar is lighter, more efficient, “newer” and popular. It is a great brand and engine!! HOWEVER, if you plan to cruise to more remote parts of the world, the Mercedes is a 60 year-old design and comprised of mostly commercial truck engine parts (often a direct part-number exchange). Once you leave the First World, Yanmar spares and shade-tree mechanics become increasingly rare and costly. Most parts of Africa, South America, Middle East and Oceana will have Mercedes and Perkins parts rusting on a shelf, and the guys that have beating on them for three generations. This is Informational only. If given a choice, I too may have been tempted by the Yanmar, but my point is that sometimes “strategic” outfitting is warranted, depending on your itinerary. Nonetheless, you have a nice new Yanmar, one which should provide many years of reliable service. It’s nice to know that when the anchor is dragging, the wind blowing onto a lee shore and Sarah’s eyes looking at you the size of saucers, that the Yanmar will start on the first crank.

    Hang in there guys!! What your doing is "worth it"! Sometimes, it can seem too much! Endless To-Do lists. Not enough money. Heat, humidity, constant mustiness. A stuffy cabin that is too small and everyone getting on each another’s nerves. “Choosing” to live this lifestyle seems sadomasochistic. But when in doubt, just take a gander over at I-95 and all the schmucks waiting in line to serve their penance at the telemarketing call center job. Say a little prayer for them, and get back to knocking out one little job at a time.

    Good Luck,
    Kapt Ken
    s/v Ocean Gypsy
    Bradenton, Florida

  8. It was really insightful.
    Thanks for such a nice content.
    BTW if anyone interested more have a look sawfinder.com thanks


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