Skerry rubrails

Within a week of launching my Skerry one of the rubrail joint failed, fortunately not while it was in the water.

There are 2 layers and the scarf joint of the outside one failed. Nothing broke, just the epoxy joint came apart. The wood is very stiff and I had  trouble getting it to bend enough in the first place.

I am considering the alternatives to repair. I epoxied the joint and clamped it closed and it is holding but I certainly consider it likely that it will fail again.

I' m thinking of either putting a brass plate 5/8 inch x 18 covering the outside of the rubrail with brass bolts to the inside. This would support the scarf joint and prevent it from opening again.

Maybe I could get away with just bolts with washers.

I thought also of actually cutting some ot the outside material including part of the offending scarf and applying a wood patch along the outside of the gunnel and putting epoxy cloth over the whole patch top and bottom plus on the outside edge. 

How do you deal with gunnels when the outside layer gives way in this manner?

I have taken the Skerry out a number of times now (with clamps on the gunnels in order to eliminate the strain on the scarf joint) and I love the boat. It is everything I expected.

All the best

Christine DeMerchant 

11 replies:

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RE: Skerry rubrails


I'm just finishing a Chester Yawl and decided to use fasteners along the entire rubrail in addition to epoxy.

I used screws every 6 in. I bored bungs from yellowheart and epoxy / countersunk them into the rubrail. The yellowheart accents against the mahogany is striking and very classic looking.


RE: Skerry rubrails

Hi Ed

My concern with putting screws along the rubrail is that it might actually weaken it. Maybe though the epoxy keeps it together. Have you put your boat in the water yet. Has it been tested?

I bet it looks really nice. Any photos eh?


RE: Skerry rubrails


The only time I've ever seen a scarfed joint fail is when it was starved of epoxy or not allowed to cure completely. If you put it back together such that it was full of thickened epoxy, that some squeezed out from every part of the joint and that the clamping pressure was enough to hold it together but not squeeze it dry, then you should be good to go for the life of your boat.

Your concern about the screws is a valid one. Not only do screws act as stress concentrators, but since they have a different coefficient of thermal expansion than wood they will eventually work loose. Then you end up with lots of little knives slicing your wood.

If you really feel the need to use fasteners of some sort, do like the old timers and peg it. That is, drill holes through the rubrail and hull and glue a piece of dowel into the hole. It should be a snug fit but still have some space for the epoxy glue.

As far as reinforcing from the outside, a strip of fiberglass along the outside will be plenty. Since the stress direction is along the length of the rail, glass on the top and bottom would be useless weight & work. If you can get it, unidirectional glass with the fibers oriented along the length of the rail is best. Otherwise, just a couple of feet of leftover cloth from the hull should work. It should even be possible to fair it in and varnish it to nearly invisible.

But if you really have repaired the scarf as described above, you shouldn't need any of this.

Good luck,



RE: Skerry rubrails

Hi Laszlo

Thanks for the awnser.

I did in fact put lots of epoxy on the joint and it did squeeze out in a very satisfying way. It was also allowed to cure for many days. 

The epoxy seemed to have not stuck to the wood on one side. I certainly made sure that the epoxy was buttered on properly on both sides.  

I'm afraid that the wood itself might have "repelled" the epoxy. Nowhere else on the boat have I had an epoxy failure. If that's the case I am probably in trouble. Hopefully I'm wrong.  

I think pegging might work but I'm wondering how the peg will keep the joint from springing open again. Would a peg have a tapered shape? 

I will put a strip of fiberglass on the outside. That at least is easy. I hate to sand that varnish though! Oh well it is already scratched and I had one big bubble or two on the first day in the sun. I think the varnish simply had not dried sufficiently and the escaping solvent made a bubble. Heartbreaking but entirely fixable.

RE: Skerry rubrails


I've had scarfs pop;  always aggravating.  Sounds like the endgrain of the scarf just sucked up the epoxy resin. 

To be extra cautious, scrub the open scarf with sandpaper if you can, and then some solvent.  Let it dry for a day.  Then on with more epoxy.

Make up a temporary "splint" out of flexible material, about the same thickness as a single layer of the rail, and protect it with tape or plastic so it doesn't stick.  Then clamp up the "sandwich" and let it cure in plenty of heat. 

RE: Skerry rubrails

I read your message after working on my Skerry, John. Fortunately I did not differ much in my approach. I first joined the failed joint with thickened epoxy resin and let it set with a c clamp holding everything loosely together so the joint would not be starved. Later I sanded all the varnish in the area and put a  fiberglass patch over the outside edge, top and with a slight overlap to the bottom. That is now setting. I will add a couple of coats of elpoxy or at least enough to imbed the cloth. Then I will sand and varnish again.


THEN I will go sailing.

I'm doing this work at the sailing club now that this is where she lives. Everyone comes and looks at the boat and I get lots of compliments. It certainly is a pretty boat. (They are not commenting on the finish either, unfortunately) The lines are lovely.



RE: Skerry rubrails


Pegging works simply by providing more surface area for either friction or glue (depending on the type of joint) to work on. It also resists the shearing forces between the 2 layers of the rubrail. There's no real need to taper the pegs in this application.

The kind of starvation John describes is exactly what I had in mind. On my boats I apply a coat of unthickened epoxy to the joints and let it get soaked up by the grain while I'm adding thickener to the rest of the batch. No problems with starvation.

Sounds like you have it well in hand, have fun,



RE: Skerry rubrails

Christine, you wrote

>>I'm afraid that the wood itself might have "repelled" the epoxy. 

I am just curious--what kind of wood is it, that caused you to wonder?


RE: Skerry rubrails

The wood was sold to me as "Mahogany" It looks like it too. There were alot of boards and were all labelled as mahogany but were very different in weight and grain as well as colour. It looks to me that any wood more or less similar got thrown in and labelled mahogany. The board I bought had nice straight grain, was heavy and almost knot free.

I think that the first cuts I made for the scarf joints were very smooth and there was not much roughness for the epoxy to attach to. I also think it likely that the end grain of the scarf joint actually sucked up enough resin to starve and weaken the joint.

The wood was exceptionally rigid as well so that I had some trouble getting the boards to bend enough to attach to the boat. After pre-bending with weights it seemed to work but it was still a fight to get them on. 

I've re glued after roughening up the edges, added a ribbon of fiberglass cloth to the edge and a bit on the bottom and top surfaces and epoxied this in place with a couple of layers of resin.

So far its holding and I went out in pretty rough water today so MAYBE touch wood (mahogany or not) they will hold and I can deal with another problem that is sure to come up! 

RE: Skerry rubrails

Just for future reference on stressed scarf joints such as rubrails, gunnels,chines etc it is always wise to coat the joint with unthickened e-poxy and wait 10-12 minutes to check then and see if the surface is sucking up the e-poxy if not go ahead and thicken up your E and glue the joint if it appears dry put on more thin and wait a few more minutes before thickening this way we do not end up with a starved joint before we even clamp it up also remember do not over do the clamp pressure as that is a sure way to fail 

RE: Skerry rubrails

Thanks, Christine.  I'd wondered if you had perhaps chosen a wood that was incompatible with epoxy unless treated (as teak and some species of oak are).

I guess not, though.

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