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mast step installation

Discussion in 'Canoe Sailing' started by DAVID EDGERLY, Nov 29, 2009.

  1. DAVID EDGERLY

    DAVID EDGERLY Enthusiastic about Wooden Canoes

    I have been wanting to install a mast step in a 20' guide model canoe but did not want to put holes in boat.can i epoxy step in bottom of boat.
     
  2. john hupfield

    john hupfield fire starter/wood burner

    I would tend to make a block big enough to cross two or three ribs,with cut outs for the ribs and screw and glue with 5200 at the ribs. This would allow some hope of removal at a later date if required. Epoxy would work but would not be removable.
    John
     
  3. Fitz

    Fitz Wooden Canoes are in the Blood

    Two bolts

    David:

    I installed and Old Town mast step from another OT in my OT Guide. The step straddled a few ribs, two bolts were installed through the keel, planking, ribs, and secured with nuts in the step. I think they were machinists slotted bolts which fit tightly and could be secured tightly with a screw driver. I used no bedding compound that I recall, and have no leaks, and you can remove it if need be.

    Fitz.
     
  4. Michael Leone

    Michael Leone You call that a sail?

    No Glue

    I would use screws as well and avoid the glue in order to facilitate future repaires or removal.
    I believe old town used four screws, two on each side of the mast socket
    going into the keel.
     
  5. OP
    OP
    DAVID EDGERLY

    DAVID EDGERLY Enthusiastic about Wooden Canoes

    What is the 5200 you speak of and should screws have some sort of washer to be beded down against fiberglass exterior
     
  6. john hupfield

    john hupfield fire starter/wood burner

    3M makes a rubber like adhesive available at most marine supply stores. It is often used as a bedding compound but has very strong adhesive properties. Usually a hot knife is used to force release, or you dismantle the partner with a chisel. You would need very little, enough to cover the ribs below the mast partner. The screws would be used top down to secure the partner and bed out (squeeze out excess adhesive). Sikaflex could also be used, though I rate 3M 5200 higher. That gives 2 options. I assume the 4 screw system would also be top down and would work to prevent sideways movement.
    If you had an inner keel that would also work for securing to.
    John
     
  7. OP
    OP
    DAVID EDGERLY

    DAVID EDGERLY Enthusiastic about Wooden Canoes

    John
    I have no keel should I still put screws from mast step to 5/16" rib that is not much to hold screw.
     
  8. Todd Bradshaw

    Todd Bradshaw Sailmaker

    I wouldn't. I doubt that small amount of thread into a cedar rib is really going to make any difference in the shear strength of the bond - and it is shear strength that's at play here. The forces on the mast are trying to slide the step out of position on the floor, not lift it away from the floor. Sailing also creates down-force on the mast, which is probably a helping factor here. Once you exceed the grain strength of the cedar ribs with your step-to-ribs glue bond (which isn't particularly difficult with good glue or epoxy) that's all you have if there is no solid structure to bolt or screw into. With adequate surface area for your glue bond though, I expect that it will work fine. Just don't try to set any records for "world's smallest mast step" in the process.
     
  9. john hupfield

    john hupfield fire starter/wood burner

    The screws help align the step and force a gppd bond. The screws alone will not secure the mast step. Once they are in then leave them there.
    Say the mast step is 1 inch oak or mahogany, pre-drill the holes to fit over the ribs, check the fit is close. You may wish to do cut outs to make the step fit over and around the ribs.Put a pilot hole through the rib to avoid splitting. This hole would be tighter than the screw whereas the screw holes in the step need only be smaller than the srew head.
    5200 is a good gap filler but great gobs is just messy. Screw down with Robertson head (if available) # 8 or #10 SS or Bronze srews that can penetrate the rib but not the hull.House screws rust and rot. Brass screws strip and break but may work in this circumstance. Under compression the adhesive works better but you just want to torque the screw snug, not strip the wood in the ribs with that extra twist..
    Tis a cut and fit job. Don't rush and it will be easy enough.
     
  10. Todd Bradshaw

    Todd Bradshaw Sailmaker

    This is why I wouldn't bother with the screws. Shown is a #10 bronze woodscrew. Even if the screws penetrate all the way to the far side of a 5/16" thick rib, and even if you drill the hole with a tapered bit made specifically for that screw size, like a #10 Fuller countersink/counterbore, you still only get about two to two and a half decent threads into the cedar. You would likely be able to put on a glove and easily rip such a screw right out of the wood - or push it sideways until it tore out. The bond here is clearly a function of the glue, and the screws could be replaced with a weight while the glue dries without having to perforate either the rib or the mast step. There have been some big, highly-stressed multi-hulled sailboats built using only epoxy bonds in their hulls and no mechanical fasteners. A canoe with 55 sq. ft. of sail area is a piece of cake by comparison and a properly glued-in step should be strong enough to break the ribs before it comes loose.

    Personally, I would use slightly thickened epoxy as it's a better long-term water barrier than goo in a tube. I would use Honduranl mahogany (not Phillipine) and pre-seal at least the underside and end grain of the step with a couple coats of epoxy (and the insides of the mast hole in the step). Varnish might fit in better with the rest of the boat for the visible top surface than epoxy coating. I'd sand the varnish off of the ribs where the step will go, leave it at about 80 grit, sand and rough-up the epoxy coating on the bottom of the step, pre-coat the ribs with a light coat of plain epoxy and then glue the step down using a mixture of epoxy with a bit of cotton microfibers mixed in. You don't need a tremendous amount of clamping pressure with epoxy, so I'd just put a weight on it until it hardened. Final sand, clean and varnish the top. If you ever need to remove it, about 140 degrees with a heat gun will soften the epoxy and you should be able to carefully peel it off.
     

    Attached Files:

  11. Andre Cloutier

    Andre Cloutier Firestarter. Wicked Firestarter.

    John, you've not mentioned a rigging deck yet - leeboards and the sail could be adaped to it, then all that would need to be made would be the deck and a mast, preventing holes in the boat, as was the original mandate. Plus the options of tuning and positioning would be unlimited. Just a thought, not sure how much sailing David wants to do.
     
  12. john hupfield

    john hupfield fire starter/wood burner

    Andre is right though then that is more complicated to build and I charge about $475.00 + shipping including leeboard.
    2 options shown are both valid. Just dry fit it with mast prior to gluing.
    Weights might work but mine usually want to shift position.
    Epoxy works but it is permanent.
    John
     
  13. OP
    OP
    DAVID EDGERLY

    DAVID EDGERLY Enthusiastic about Wooden Canoes

    Thanks todd

    I like to use the epoxy is the wood selection critical I don't have any mahogany. also should I install mast step for a 90 degree mast
     
  14. Todd Bradshaw

    Todd Bradshaw Sailmaker

    I'd probably avoid oak, since epoxy and oak don't always get along too well in terms of bond strength. Ash would work and epoxy does work pretty well with ash, but you really need to seal ash well or it gets black mold down in the grain that pretty much has to be ground off. As long as it's well sealed and that finish is maintained, I wouldn't have a problem with ash, maple, cherry, walnut or birch. It will get wet in use at times, but we don't generally leave our canoes sitting full of water for extended periods of time. If we can make good paddles from these woods (which we can) they should also work fine for a simple mast step in a day-sailed boat with dry storage.

    Mast rake is possible, but whether or not it's desired usually depends on the rig. It is more common to keep the mast pretty close to plumb. The advantage of a raked mast is that as you ease the sail outboard to sail downwind, the tail end of the boom raises a bit. If you're heeled over, it offers a little bit more clearance before the boom's end hits the water. Rake can also be used at times to move the sail's Center of Effort back a bit if it's needed to get the rig to balance properly (usually not needed on a canoe since our rigs and leeboard brackets are adjustable).
     
  15. Michael Grace

    Michael Grace Lifetime Member

    Hi David,

    I’d like to suggest an alternative approach. If I were you, I’d be looking for the following: a mast step that works, stays in place, doesn’t rot, and one that doesn’t permanently alter or damage the canoe. Given these wants, I’d do this differently. Lateral forces are the concern, and that’s precisely why screws should be great. Sure you could rip a screw out of cedar by yanking on it or the step, but that’s not what the mast is doing. Heck, nails resist lateral forces- that’s their job (but use screws). Screws would work even better if they ran from the planking through the ribs into the step (i.e., from the outside of the canoe)- any chance you’re re-canvassing the canoe?

    I personally wouldn’t use epoxy either. A step of any significant footprint will likely be permanently bonded to the canoe by epoxy. If you needed/wanted to remove it, it might be very difficult because a heat gun likely won’t de-bond anything but the edges of the step- wood is an excellent thermal insulator, so epoxy at the center of the step probably won’t be affected by the heat gun.

    Ash and epoxy? If you use epoxy and then use ash for good bond, you’re inviting rot down the road (ash rots beautifully). Oh, right, you can seal the ash well before epoxying it in place… but then you don’t need ash because the epoxy bond is no longer to the wood- it’s to varnish!

    There are untold numbers of Old Towns out there with white oak steps, not epoxied in place, but rather screwed on from the outside of the canoe. When I’ve removed many of these, they appear to have little or no varnish on the bottom of the step, yet they’re not rotten, they’re not permanently bonded, and they’ve never ripped out. So if I were doing this, I wouldn’t reinvent the wheel, but do it as it was done before. If the canvas were good, I’d apply a pre-varnished oak step from the inside using screws and perhaps a non-epoxy glue (like Titebond III; though I don’t know how well Titebond bonds to varnish), knowing that it might need to be chiseled out if you ever wanted to remove it.
     
  16. Todd Bradshaw

    Todd Bradshaw Sailmaker

    I believe that he stated earlier in the thread that the boat has no keel to bolt to. I could be wrong, but I don't think recovering the hull was intended to be part of the plan for installing a simple mast step. Tightbond doesn't stick worth a crap to varnish. Epoxy will, but nobody in their right mind would leave the varnish in a spot where they plan on using epoxy - which is why I specifically stated that it should be removed before bonding the step to the ribs. Varnish is actually a very poor sealer for any area that you can't readily get to to maintain and recoat. Epoxy is drastically better and the best you can buy - which is also why I suggested that ash should be sealed with epoxy, at least on its underside and end grain.

    The idea that an epoxy bond can't ever be removed is pure bunk. If you have trouble due with the heat gun due to the insulating value of the wood (which is unlikely because it doesn't need to be that hot if you work carefully) then you get out a router, shave the step down to about 1/8" thick and then heat what's left and peel it off. No big deal. The fact that there wouldn't be any screws in the step to hit with the bit makes it a simple job.

    This thread is going downhill fast - mostly because people don't read carefully.
     
  17. Michael Grace

    Michael Grace Lifetime Member

    “This thread is going downhill fast - mostly because people don't read carefully.” Ha! No kidding!

    David- there are multiple ways to do this. Read, think and do what seems best for you. Old Town certainly did it many, many times and their methods seem to have worked well. Other methods will work, too, depending on how many people are going to be snatching on your screws, whether you want the job to be easily reversible, and whether or not routers and heat guns are exciting for future projects on your canoe. But whatever you do, make darn sure you read carefully! No one said you should re-canvas solely to put in a step, and no one stated the horrible "bunk" that epoxy cannot be removed.
     
  18. OP
    OP
    DAVID EDGERLY

    DAVID EDGERLY Enthusiastic about Wooden Canoes

    Thanks to all

    I think the epoxy was my idea originally but did not know if it would work. Did not want to drill holes in boat or re canvas. This is why i will epoxy the step in the canoe.
     
  19. Todd Bradshaw

    Todd Bradshaw Sailmaker

    ..."no one stated the horrible "bunk" that epoxy cannot be removed."

    Which all just goes to show that you still haven't read the thread carefully.

    Post #2 - last line - "Epoxy would work but would not be removable."
    Post #12 last line - "Epoxy works but it is permanent"
    Post # 15 (your own post) first line - "I’d like to suggest an alternative approach. If I were you, I’d be looking for the following: a mast step that works, stays in place, doesn’t rot, and one that doesn’t permanently alter or damage the canoe."
    and also in #15 - "A step of any significant footprint will likely be permanently bonded to the canoe by epoxy"

    Post #7 - " I have no keel should I still put screws from mast step to 5/16" rib that is not much to hold screw."
    Post # 16 - "Forget the 5200, glue, etc. Bolt the step through the hull into the keel."

    "The way Old Town did it for years" may not have much bearing here, since they generally had the luxury of working through the entire hull and/or keel. If the intent here is to mount the step in an existing keelless boat without having to re-canvas, you are left with an glue bond and/or maybe the tips of a few of screws trying to get a grip on a thin cedar rib. I maintain that the glue bond alone is a better bet and that the screws won't have enough grip or penetration depth to really add anything to the mix other than holes in the wood. If you're going to seal and glue two hunks of wood together on a boat, you might as well use the best sealer/adhesive available, and that's epoxy resin - despite the WCHA phobia about it. With careful work and reasonable maintenance, it should be good for decades and look just as good and appropriate as any other part of the boat. It sure beats sailing around wondering when the tips of the screws might tear out or a Tightbond-to-varnish glue job will fail.
     
  20. Michael Grace

    Michael Grace Lifetime Member

    You are so perfectly correct in your literal interpretation. What on earth is absolutely permanent? Damn! Get enough power and you can bring down the Hoover Dam! It's hard to forget the last thread that devolved just like this into silly drivel simply because someone couldn't accept by alternate opinions without feeling insecure. Epoxy IS permanent (relatively, of course) with respect to other options. In #15, the point was that applying the step with epoxy surely is relatively permanent without resorting to a router, a heat gun, etc. That's a heck of a lot more "permanent" than removing a few screws. But SO WHAT? So someone missed the line that there is no keel... some people took a looser interpretation of permanent than others... and one person even apparently assumed that screws can't be unscrewed prior to using a router on wood... and someone claimed that another person said the canoe should be recanvassed (really?!). But SO WHAT? Apparently David was able to make up his mind even without having to witness an ego on parade.

    "The fact that most members of this forum don't believe me doesn't really surprise me at all. This place tends to be very close-minded about such stuff."

    "the WCHA phobia"

    and on it goes... Must be difficult to be so perfect in such an imperfect world.
     

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