PVC Dinghy Rails

[Idaho]

About 25 years ago I built up a 10-foot f/g dinghy hull with seats, mast step, rudder and edge rails. This thread is about replacing the original 25yo oak laminate rails with PVC.

After 25 years the glue-lam oak rails were delaminating and freshwater rot had begun. I did try to keep up with the varnish, but time overcame intent. New rails were needed.

I found PVC for outdoor fencing at Home Depot. It is lightweight, flexible, and is sun and weatherproof. It has a lightweight center with a harder surface. It is not really strong enough to use fasteners in it directly.

I found online PVC rod stock. It is very dense and is much harder than the fence material. I ordered 10' of 5/8ths inch diameter rod. But they sent 1" instead. I called to discuss and they sent the 5/8th and told me to keep the 1" for free.

I bought two forstner drill bits, 5/8th and 1 inch, and a pot of PVC cement. I cut the rod into short pegs, long enough to just be a bit short of the two thicknesses of the fence material plus the thickness of the f/g hull. On one end of each peg, I ground a short taper so hammering them into the holes would be easier.

I removed the old oak rails, one at a time, to keep the shape of the boat, then clamped on the PVC fencing to the first bare top edge.

I marked 5-inch intervals and drilled a few 5/8th holes, almost through, stopping when the centerpoint of the drillbit just emerged. Swabbed some glue in the hole, and hammered in a peg. The excess glue squirted out the tiny hole from the drill centerpoint.

All along the rail, every 5" got a peg. This results in a stiff, strong rail that is weatherproof, does not need varnish or paint, and will last for decades.

The oarlocks were attached by drilling a 1" hole all the way through at the 4 points where bolts were needed to attach them. Then glued and hammered in the 1" pegs. Then drilled a 1/4 inch bolt hole through the center of each peg, and bolted on the oarlocks.

The rod is much harder and stronger than the fencing. It holds through-bolts much more securely.

There is a pic of work in progress in my photo album here.

Glad to answer questions or clarify.

[Cheechako]

Interesting. Pics would e nice.

[Idaho]

Pics of the rail project in my albums.

[Cheechako]

Originally Posted by Idaho

Pics of the rail project in my albums.

Albums...? No pics in your gallery..... What are 'albums'? No link comes up hovering over any words in your post? Maybe my 'linky no worky'

[Idaho]

https://www.cruisersforum.com/forums...lbums6122.html

Link to project photos.

[Cheechako]

That looks nice! It's not heavy stuff? I guess it's more that lightweight 'foam' type pvc...

[Idaho]

Originally Posted by Cheechako

That looks nice! It's not heavy stuff? I guess it's more that lightweight 'foam' type pvc...

The fencing material is lightweight. Looking at a cut end shows the structure. The center isn't really foam, but it is less dense than the outer surfaces.

The PVC rod is very dense and heavy. It is much stronger than the fencing. When a peg is glued into the rail, the 1/8th inch thick hull securely holds the peg as the glue holds the inner and outer rails together.

The face of the fencing is not glued or bedded to the hull. It is securely held on via the pegs every 5 inches.

[Idaho]

Sailboats are interesting.

[Jammer]

Sounds like a good repair. I wonder what kind of glue you used. PVC can be joined with cement but doesn't bond especially well with most other adhesives.


I am in the middle of a dinghy build myself and have settled on fir gunwales with an EPDM bumper from Port Townsend Watercraft. It is the same bumper extrusion they sell for their PT Eleven.


I had considered many gunwale materials. The ideal material is resilient, long lasting, and does not damage or mark other boats when alongside. Among hard plastic materials, UHMWPE and MDS-filled nylon were candidates with the MDS-filled nylon being more UV resistant. But feedback from people who had cruised extensively was that this did not provide sufficient fendering and was, if nothing else, likely to make me into a pariah when trying to visit neighboring boats. That left fabric-covered foam and the EPDM bumper.


Anyway my two concerns with PVC are that it isn't really that UV resistant and that it doesn't provide any cushioning, and is more likely to mark other boats or crack in a mild collision than either UHMWPE or MDS-filled nylon.


But do let us know how it works out.

[Idaho]

I used standard pvc cement.

The rails are not glued to the hull. The pegs are glued to the inside and outside rails, pinching the hull every 5 inches.

The fencing material for the rails is designed to be outside in the sun. Only time will tell if it holds up on a boat.

[Jammer]

Originally Posted by Idaho

I used standard pvc cement.

The rails are not glued to the hull. The pegs are glued to the inside and outside rails, pinching the hull every 5 inches.

Should work fine. (Cement and glue are two different things and I wasn't sure what you meant originally)

The fencing material for the rails is designed to be outside in the sun. Only time will tell if it holds up on a boat.

To some extent it will depend on your expectations. PVC pipe and conduit are supposed to be sunlight resistant, and while they are to a degree, they become brittle and chalky over the course of years. And it does have the advantage that you can attach it with cement and pins as you have done.


This is what I was looking at before going with the EPDM bumper, but it has to be held in place with mechanical fasteners:


https://www.mcmaster.com/mds-filled-nylon/


The EPDM bumper I ended up using is here:


A Bumper for the PT Eleven | Port Townsend Watercraft BLOG