Author Topic: 30' GA in Elma Wa.  (Read 2782 times)

0 Members and 1 Guest are viewing this topic.

Brian.Dixon

  • Administrator
  • Commodore
  • *****
  • Posts: 1955
    • View Profile
    • Glacier Boats of Alaska
Re: 30' GA in Elma Wa.
« Reply #60 on: February 27, 2021, 09:51:51 AM »
I would say that it would work well.  That would be a lot of square inches and not much force.

Since the ratio of square inches of adhesive to square inches of UHMW stays the same no matter how large the piece is that you're gluing on, I'd agree.  But then my wee little brain thinks about how near the centerline of the plastic, you might see a tiny bit of movement ... per inch .. which adds up to a lot more expansion near the outer edges ... perhaps enough to delam the plastic from the adhesive near outer edges?  Perhaps, like all good things in life, a complementary solution may address all of the above.  If there were screws or slotted rail or some type of mechanically-limiting solution near the outer edges, the combination of gluing the whole bottom on PLUS the outer-edge fasteners (or rails or ???) might be the magic ticket for large jobs.  I plan on designing a wood/glass/epoxy jet sled, when time permits, and it would be nice to know how best to protect the boat from river boulders and tough beachings...

The Great Alaskan - Professional performance - Easy to build! - https://www.glacierboats.com  ><((((> .`.><((((> .`.><((((> .`.><((((>

Grady300

  • Lieutenant
  • ****
  • Posts: 336
  • Chuck
    • View Profile
    • West Coast Boat Works
    • Email
Re: 30' GA in Elma Wa.
« Reply #61 on: February 28, 2021, 07:56:27 AM »
I am getting very close to applying my spray rails ect.  I am concerned about having un-glassed wood in the water.   At some point I am sure I will beach my boat.   Has anyone glassed over UHMW?  I am thinking that if I poke a hole in the glass I won't have anything to rot.
Aux. spray rails I went with mahogany just glued and screwed. let dry 48 hours removed all screws and drilled the holes out a bit and filled with peanut butter so there should be no water should enter the hull. Put several coats of epoxy on them then bottom paint primer with bottom paint over that. No glass whatsoever on the aux. rails I think the aux rails will out live me :) main spray rails are mahogany pre-glassed before install on the boat. Just my 2 cents
P.S.Edit...I should mention my pre-glassed main spray rails are not full length of the boat. I chose to go with the shorter version Brian shows it is so much easier. Mine are only about 12 feet long+- 
« Last Edit: March 03, 2021, 07:14:37 AM by Grady300 »
CNC Cut Kits For The GA Available
www.wcboatworks.com
Last Completed Build 21'4" Tolman Wide Body CC
28' GA Might Be Next

ghelland

  • Midshipman
  • *
  • Posts: 29
    • View Profile
Re: 30' GA in Elma Wa.
« Reply #62 on: February 28, 2021, 04:25:13 PM »
Thanks for the input.  I am hunting down some IPE to do the job.  If it only lasts 40 years I guess I won't care by then. 

rhenryinoregon

  • Sub-Lieutenant
  • ***
  • Posts: 136
    • View Profile
    • My YouTube Channel
Re: 30' GA in Elma Wa.
« Reply #63 on: March 01, 2021, 01:39:29 PM »
Gary,

Just curious if the UHMW shoe on your driftboat was attached by screws only?

I would not use UHMW if that was the case.  You have some time to make a couple samples to see how it sticks with some g-flex, / flame treated one with screws on 8" centers or so and one with just screws and the end.

I would use G- flex on whatever shoe you choose.

G-flex stuff:
https://www.westsystem.com/specialty-epoxies/gflex-epoxy-adhesion-data/

And Reltek Adhesive for UHMW:

http://www.reltekllc.com/adhesivesforuhmw.aspx

Yes, it was just screws - bronze I believe. There were a lot of them and they were counter sunk flush. It was worst on the sides and the dry rot hit the edges of the bottom and into the chine frame. There may be adhesives that stick to UHMW but not any Ive tested. No hook. Again, Im hardly an expert but that was my experience.
Randy Henry, SILVERTON Oregon
Randy_Henry@msn.com

Todd j

  • Captain
  • **
  • Posts: 892
    • View Profile
Re: 30' GA in Elma Wa.
« Reply #64 on: March 01, 2021, 05:21:47 PM »
I am getting very close to applying my spray rails ect.  I am concerned about having un-glassed wood in the water.   At some point I am sure I will beach my boat.   Has anyone glassed over UHMW?  I am thinking that if I poke a hole in the glass I won't have anything to rot.
Aux. spray rails I went with mahogany just glued and screwed. let dry 48 hours removed all screws and drilled the holes out a bit and filled with peanut butter so there should be no water should enter the hull. Put several coats of epoxy on them then bottom paint primer with bottom paint over that. No glass whatsoever on the aux. rails I think the aux rails will out live me :) main spray rails are mahogany pre-glassed before install on the boat. Just my 2 cents :)

Please do let us know how preglassing the spray rails goes for you.  I tried to preglass and failed, gave up, and went a different route.  For me I think was a bit of a blessing.  FWIW  The spray rails are a rascal!  I did one side unassisted, it was harder than the unassisted flip.  The scarf joints busted during install.  I tried to do them multiple times and said screw it.  I just scarfed them on the boat and they look great.  I don't know how readily the preglassed wood will bend to the boat.  Its asking a lot of it for the forward third of the hull.  I used 2 layers of 6 oz. glass cloth at 45 degrees to the edge  per Brian's suggestion.  Super easy and super strong.  I also used no mechanical fasteners on the forward end as the manual calls out.  Do look ahead at how far the spray rails go forward as I have seen instances where they do run too far forward and cause trailering or other unforeseen complications.  I held mine back just a smidge more from the stem to avoid this and I think they look just fine.

my .02 FWIW

Brian.Dixon

  • Administrator
  • Commodore
  • *****
  • Posts: 1955
    • View Profile
    • Glacier Boats of Alaska
Re: 30' GA in Elma Wa.
« Reply #65 on: March 02, 2021, 06:47:27 AM »

Yup ... those spray rails can be challenging to install ... almost impossible by yourself.  You really need to draw a line on the boat where they go, use washers and through-bolts, have someone inside the boat to feed the bolts through holes, someone outside the boat to put on washers and nuts and tighten, and a 3rd person carrying the long end of the rails and lifting up/down to keep the spot being through-bolted at the moment right on the line.

Glassing ahead of time puts fiberglass in tension when bending onto the boat ... tough cookies.  If you must, then just glass scarf joints.  Try NOT to have any scarf joints in the front third of the hull where the hard bends are.

The long screw that's recommended at the bow goes into the stem (or add a doubler inside if the rails don't go all the way to the stem).  If you bang up the rails and don't get them repaired right away, they can absorb water and create tremendous 'straightening' force on those rails (the bent shape on the boat is not their original shape).  This risks the forward end breaking the epoxy and popping off the boat.  Saw it happen once.  The screw at the bow is the SINGLE fastener that I call out for the build, and this is why... mechanical back-up for the aforementioned scenario.  The rail that I saw pop off was 2 layers of mahogany ... it's possible that if you are layering plywood to build up the rails, that this issue goes away.  Plywood, having alternate directions of fiber in the plies, has only half the wood with fore/aft fibers that would 'want to straighten' if absorbing water AND the glue layers between plies will slow most water absorption deeper into the wood. Just a few thoughts ...



The Great Alaskan - Professional performance - Easy to build! - https://www.glacierboats.com  ><((((> .`.><((((> .`.><((((> .`.><((((>

Todd j

  • Captain
  • **
  • Posts: 892
    • View Profile
Re: 30' GA in Elma Wa.
« Reply #66 on: March 02, 2021, 07:46:27 AM »
I used nice meaty fillets top and bottom too

Brian.Dixon

  • Administrator
  • Commodore
  • *****
  • Posts: 1955
    • View Profile
    • Glacier Boats of Alaska
Re: 30' GA in Elma Wa.
« Reply #67 on: March 03, 2021, 07:11:50 AM »
I used nice meaty fillets top and bottom too


... Always a great idea.  Nice big fillets direct water outward rather than allowing it to try to force in between the hull and rail ... AND provides lots of extra strength.

The Great Alaskan - Professional performance - Easy to build! - https://www.glacierboats.com  ><((((> .`.><((((> .`.><((((> .`.><((((>