Spray rails

[Todd j]

Food for thought.  I used CVG fir in 2 layers as laid out in plans.  I covered them with 3 layers of 6 oz. Cloth.  I made wide tape by cutting the cloth on a 45 and laying it over the spray rails at a 45. Anyway, I have twice now hit/bumped different docks where only the spray rail made contact.  The point load on such a small profile was enough to damage the paint and force me to consider repairs in the near future.
   I understand that poor boat handling is really at fault here.  I if I could go back in time with what I know now would really think about using UHMW for the second- outer lamination of the rail or use a much harder wood.  My boat is a beautiful machine and I intend to use her, but it hurts.  Every ding hurts!

[Brian.Dixon]

A harder wood such as mahogany can be used - you may need to cut the layers thinner to get them installed and I'd definitely recommend that you don't skip the one screw up forward into the stem.  Damage to the rails that expose the wood to wet can cause the wood to expand hard enough to pop off the hull.  I've seen this once, with mahogany, but they'd skipped that reinforcing screw.  I believe that when the rail expands (due to unrepaired damage that exposes the wood to water), that it separates at the very end (f'w'd) first ... the screw makes the bond stronger, so the crack never starts.  It's the only required piece of metal left in the boat (per instructions).

UHMW is fine, but it expands and contracts a lot in the lengthwise direction.  You have to use a tight screw schedule, say not more than 6" apart (especially in the curvy sections), else it will 'work' the screws until the loosen ... which can let water get to wood.  Rubrails are tricky.  The easiest thing is to just fiberglass as you did and then repair as soon as damage occurs ... taping off the rubrail and repainting is pretty easy.

[Todd j]

I have lots of paint too, I need to do a test panel and see how it looks.  At the minimum I can coat with unthickened epoxy to stabilize the cracked paint.  For some reason I remember the spray rails not reaching the stem enough to screw into it.  I know mine are not close enough to the stem to reach at any angle.  I think there was some discussion of this buried in my build thread

[Brian.Dixon]

Yeah ... it's on page 108 of part 1 (of 2) construction manuals.  It says that 'you MAY wish' to leave a #10 x 2" stainless screw through the forward tip of the spray rails into the stem, and that you want the spray rails to terminate within 2-1/2" of the bow point so that you can screw into the stem.  Number one, it's OK if you did not do this, as long as you realize that spray rail damage must be repaired and coated epoxy again where necessary to waterproof the repair.  Number two, the same reasoning can be applied to wood rubrails along the gunnel if that's what you did.  Another option is to put a block inside the hull that you can screw into.  MOST people don't heed any of this advice (!) and just maintain their rubrails and splash rails to prevent issues ... which is fine.  As long as everyone recognizes that water absorption into rails in the f'w'd curvy regions can try to 'straighten' the wood with great force and pop it off the hull at the bow.  As mentioned, I've only seen this once, and it was a case where raw wood got exposed and was left unrepaired while the boat was used a lot and the water absorption occurred.

[Todd j]

No screws in my rails, just heavy fillets.  I will keep an eye on the bruises.  My boat lives outside and gets used year round.  I would hate to epoxy ?in? moisture

[Brian.Dixon]

I suspect that water absorbs in slowly, so a week in dry weather ought to be long enough?  Does your spray rail shape have a flat surface that could get a strip of UHMW added?  3/4" would be best.

[Todd j]

Not without major surgery.  I just need to improve my boat handling.  I have found out that my boat is subject to things a tin boat is not.  I figure there will be repairs and repaints in her future.  The cockpit deck already shows much wear

[Brian.Dixon]

 ...Showing much wear just means you're having much fun