home made mast tube

Discussion in 'Sunfish Talk' started by pthayn, Nov 23, 2009.

  1. pthayn

    pthayn New Member

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    I cut an inspection port this afternoon. It doesn't look so bad from the outside of the tube. I am sure that once I am done, the outside of the tube is going to be one ugly work of art. I purchased some epoxy 105 and some 205 hardener, along with 10 feet of 6" woven fiberglass tape. I think I an going to center the mast in the tube, while it is wrapped in a bunch of wax paper and then just wrap everything in tape and epoxy. I haven't bought any filler for the epoxy, but I think I will mix up some peanut butter consistency epoxy and pack it around the bottom of the tube. My main concern is where the tube attaches to the deck. Most of that area is missing, but the same approach or a wooden donut may also work. I will post some pictures soon. I am not sure what the previous kids did to this boat, but it must have close to a gallon of dirt just rolling around inside. Not really sure how to get that out, but will think of something. Also, the inside of the boat is wet, and I don't have a garage to store the boat, so it may be a while until I actually work with the epoxy.
     
  2. rob herschel

    rob herschel New Member

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    it won't fit in the dining room? :D
     
  3. Webfoot

    Webfoot New Member

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    Usually it's the wife and not the dining room that's the problem.

    Best solution to the deck would be to remove what's left of the mast tube and then start laying up a large squares of Matt and Woven Roving under the deck centered on where the tube was. When you get done, after two or three layers, redrill the hole in the deck for the mast tube. This would also give you the base for fiberglassing in the wooden donut you were talking about. Maybe best to finish with fiberglassing in the wooden block and then drilling the whole thing, wooden block included, in one shot. This would give you a fixed position for the top of the mast tube, then you only have to deal with where it attaches to the keel for getting the mast lined up.
     
  4. Wayne

    Wayne Member Emeritus

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    The back side of fiberglass work never is pretty.


    Tape ? :eek: I hope it's substantially woven fabric not the window screen looking stuff for muffler repair and holding plaster in drywall patches. The glass fabric is the structure for the resin.


    A flared fiberglass flange might take care of both needs..., deck repair/reinforcement and connection.


    Better to masking tape over all the broken out sections, otherwise you're liable to drool and puddle resin into the bottom of the tube.


    Get a couple of buddies to help you hold it bow down and shake it. Then lay the hull back down and reach into the bow with a shop-vac.


    Hmm..., yup, the parts you're fix'n gotta be dry dry dry.

    Plan your work day well... remember, epoxy - unlike polyester resin - needs to be laid up in one shot before the resin begins to cure or you loose the chemical bonding between layers that gives epoxy its extra strength for fiberglass work. If you foresee having to do the lay-up work in stages over a couple of days time, polyester laminating resin might be a better material choice.




    :D
     
  5. rob herschel

    rob herschel New Member

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    wife? wee don need nooo stinken wife!

    oops i didn't see her reading over my shoulder.:eek:

    i guess i'm sleeping with the (sun)fishes tonite.
     
  6. Webfoot

    Webfoot New Member

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    How about this, get someone to mold a deck blister like the Sailfish has at the base of the mast and put it on the SF. It looks way cool, keeps water out of the mast tube and adds support.
     
  7. pthayn

    pthayn New Member

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    The tape is fiberglass fabric, and pretty thick, about as thick as the west marine place had. I was wondering what you meant by flange? I agree about the masking tape. I'll be sure to mask it so that the tube doesn't fill, but I may leave the mast in while I apply the fabric and epoxy, or I may just use that mast and a level to line the tube up and then stuff it with newspaper.

    So is this flange something I should find, or should I just try and make one. I googled it and there are some metal ones for pipes, but I couldn't find fiberglass ones.
     
  8. Wayne

    Wayne Member Emeritus

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    Good choice!


    Maybe gussett is a more accurate term. The fabric is extremely flexible and will turn the corner to layer onto the underside of the deck.

    You just build the tube out onto the flat of the deck's underside as you lay up each of the half dozen or so layers it will require to match the original tube's thickness. (see sketch)

    Maybe mock up your approach by using masking tape to wrap and connect a TP tube to a flat piece of cardboard.

    Never use your boat for practice... always do mock-ups and even learn the behaviors of the actual materials by doing a small job on a practice piece.

    Yup, it costs a bit more to do that, but it costs even more to misjudge how things are going to work.

    By now you should have picked up a good book on working with fiberglass and doing different sorts of repairs because none of this kibbitzing is coming anywhere near the details you'll get from the instructions and methods written in the texts.

    Just to help get you going in the right direction...
     

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  9. Webfoot

    Webfoot New Member

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    The flange could be built around a plywood ring slipped over the mast, using the mast as the mold for the new mast tube. Put release agent on the plywood ring as you will remove it after the tube is made. Once the mast tube is completed, it can be inserted in the deck with the flange resting on top of the deck. Having the flange fixed to the top of the deck offers the advantage of a professional looking repair, covers the damaged deck and makes it harder to damage the deck/tube when inserting the mast.
     
  10. Porpoise2

    Porpoise2 New Member

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    Depending on what might be saturated with water inside the hull, it could take weeks before the moisture is gone. I'd leave it in an all-day sun location if possible.

    I'm now preferring the use of 206 (slow-set) hardener. Even in moderate temperatures, I've had 205 "go-off" (set up) and get too hot to hold the container. Also, the vapors produced by the heat are hazardous.

    IF the base is imbedded in foam (Laser fashion), then the base is probably strong enough without adding the gussets I previously mentioned. The deck-end of the tube is probably also strong enough, but your sketch shows an overlap at the top. Is the overlap made of fiberglass or was the overlap in the picture to indicate the missing metal ring?

    If fiberglass, then the tube is undersized for the mast.

    If fiberglass, how about cutting away the flange? The object is to make the tube strong and watertight, so...

    1) You could tape (or patch) the outside of the existing mast tube
    2) Make a new watertight tube using the mast as a male mold
    3) Insert the mast with new tube attached into an epoxy paste, and
    4) Simultaneously bond the overflow to the deck inside a wood ring with the desired finished contour.

    If there's an issue regarding erosion of the hull (from the bottom edge of the mast), you could imbed a piece of aluminum or stainless steel at the bottom of the mast step.
     
  11. pthayn

    pthayn New Member

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    Its been a while since I posted, mostly because now the weather is improving and I have working on my boat. i have updates, and one more question.

    I used the mast as a male mold and now have a mast tube thats made of fiberglass. It is smaller in diameter than the original mast tube fragment that I removed. There is still a minimal amount of the attachment point of the original mast tube to the hull, so I think I can center the new tube at the site of the old base pretty well. This will ensure that the mast tube is straight, so my mast isn't off center. My question is now that i have a mast tube (without flange) would is be better to fiberglass this to the original hull, or should I put a few layers of fiberglass on the inside of the hull, where the mast tube will connect. I am concerned to that if I I don't put down a few layer of fabric, the attachment of mast tube to hull will be weak. I also purchase to mix-ins for my epoxy, a bottle of glass microspheres for the gel coat repair, and some diced glass fibers. I was wondering if it would bestronger to try and run strips of fabric down the base of the tube onto the surface of the jull, or should I just mix in the glass fibers and glop it around the base of the tube.

    I will try and post some pictures when i am off work tomorrow.
     
  12. Webfoot

    Webfoot New Member

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    Mast tube should not be a snug fit. When you insert the mast, air/water needs to vent up between the mast and the tube. If there is water in the mast tube and you insert a snug fitting mast you have a hydraulic ram.

    Adding some extra fiberglass will not hurt a bit. Better to go a little stronger then hear a loud crack and watch you mast tilt to one side.

    Strength is in the fiberglass impregnated resin. Fiberglass tape strips or running a fiberglass-strip-circle around the base of the mast is good. Glopping does not sound like it will spread out the load evenly although I could be wrong.
     
  13. pthayn

    pthayn New Member

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    I guess I should update everyone to the progress of my little sunfish. Like previously mentioned, the mast step was rotten and mostly missing, when I bought the boat. I discussed using another material like aluminum tubing to use as a replacement. I didn't follow that idea and am very glad that I didn't. I used the mast as a male mold of the the mast step and wrapped it several times in fiberglass fabric. This requires significantly more fabric that I though it would, to build up a 1/4 inch thick pipe. I made the bottom quite a bit thicker than the to top, as it take a little more force. I thickened the top near the junction with the deck, so there would more contact for good bonding. To attach the bottom, removed all the remnants of the previous mast tube and sanded it flat, and applied about 6 to 7 layers of fiberglass. I then centered the step in place and placed and glued a 4" disposable ring around it and poured an epoxy mix with fiberlgass fiber mix in the ring to lock the base in place, it poured about 3/4 of inch thick. I then poured about the same depth of straight epoxy down the mast tube to support the mast. I then flipped boat over and placed layer of cardboard covered in wax paper with a circle cut out to fit around the top of the mast tube. I should mention that the new mast tube fit within the hole in the deck. Once the boat was upside down and the cardboard was in place, I poured a mix of epoxy and glass microspheres around the top of the mast step from inside the boat to lock the mast tube in position and attach it to the deck. Once this was set up, I just cut off the top of the mast step to desired length and it was all done. It is maybe not the prettiest repair on the inside, but it 200 years when this boat is all rotted away, that mast step will still be intact. It probably weighs 15-20 pounds.
     

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  14. pthayn

    pthayn New Member

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    here are some photos from the inside, I didn't take many during the construction process. But you can get an idea. Sorry the inside of the boat is so dirty. The last owner dumped about 5 gallons of dirt and nuts from trees inside. I think this boat had been somewhat abused. I sailed it 2 weeks ago and she took on no water at all. I also painted her to match the trailer and my car, with Rustolium top side paint from Lowes. The trailer is a modified harbor freight trailer that I replaced the tongue with a 9 foot length of 2x2 inch steal tube, and built a cradle for out of treated lumber.
     

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  15. Wayne

    Wayne Member Emeritus

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    Nicely done ;)
     
  16. AJC6882

    AJC6882 Member

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    just so everyone knows I have a spare mast step from a donor boat. For future reference.
     

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