A Photo & Discussion Forum for Wharram Design Enthusiasts
I bought a tiki 21 this summer. Its generally in good condition. I did notice that the beams needed some new paint, but when I got them into my shop, it turned out to be a little worse than expected. Many small cracks in the paint mainly along the edges of the beams had allowed much water ingress and some rot. Also it turned out the builder had not epoxy coated the holes for the bolts that holds the end-cleats. So there was bad wood there too.
SO I will strip the paint as much as possible, and repair rot in various places.
And now the question:
The normal way forward would be to epoxy coat and then paint. But would it perhaps be better to treat with some anti fungal base (or linseed oil) and the wood paint?
The idea being, that this would allow for some diffusion of water out though the paint if water get in.
It seems to me that epoxy is great if the surface is intact. Then it completely seals the wood. but if for some reason the epoxy layer is damaged (cracks), then is also seals in any water that enter the wood.
Those small cracks had certainly made the water content in my beams much too high.
Any thoughts on this?
You don't say how or what the beams were painted with and while modern paints are very good they don't last forever and are not foolproof. They do require inspection, maintenance and sometimes repair. As well as being only as strong and reliable as the substrate of course. And as you have discovered, once water gets in there is no way for it to get out. Stripping the beams completely and oiling them (look up 'boat soup') is certainly an option though I would suspect that properly sealed and painted beams are likely to have a better chance of survival and require less overall maintenance. You can always glass them for an extra layer of protection though 2 coats of PU over 2 coats of a good epoxy primer over the epoxy resin coated wood should give you years of trouble free service.
Sound like whichever way you decide to go, you'll need to strip yours back to wood and let them dry out properly anyway.
Good luck with the repairs. Here's an earlier discussion about beam rot that you might find useful.
I would recommend epoxy coating your wood. Make sure the temperature is high enough for the epoxy to be runny and the wood needs to be warm too. That way it will soak in and seal the wood.
I'm not sure about oiling the wood. This might prevent the epoxy from bonding. Note also that you can get a penetrating epoxy.
Thanks for the response.
I am not sure about the old paint, but I think its Hempel on top of a layer of epoxy.
It seems you both agree on epoxy as the best option, and I think you have a good point with the temperature Ian.
I think I will strip of the paint, and try to find a place in the house where I can store them in winter. That should dry them out.
Ian, in the other tread I saw, that you also had problems where the lashings go over the beams. How did you solve this?
On my hitia I spliced in small pieces of hardwood in the beams, but that's a lot of work. I'm thinking of just applying a patch of fiberglass on the beams, on each of the 4 places where the lashings go over.
I have to admit, I have not fixed that problem yet. There are in fact two problems, first is the small compression marks the cord/rope makes in the beam edge, and second, micro cracks which can appear in the paint where the top of the beam is forced downward by the tight lashing. These cracks are in the direction of the wood grain. They will probably let water in.
I think letting some hard wood in might work. I've also see posts suggesting epoxying small bits of copper plate in the edge. I think fibreglass or some woven glass material might work.
I should fix this over the winter and will update my blog.
I sanded the edges down into a small trough where my lashings go over and then built it up with epoxy thickened with straight silica. No issues at all anymore with the lashings cutting into the wood. Spirit of Gaia has stainless plate glued and screwed down under her lashings.