Marine Tex Question

[Tortuga]

I am in the process of repairing a section of rotted wood on an exterior door jam at home, using Marine Tex to patch the jam where I've removed the rotted wood.

Marine Tex should be a perfect material as this door is on a roof deck with southern exposure and no protection and therefore gets constant sun or rain -- nothing on between. Usually enough sun to crack the wood, and then enough rain to rot the inner wood. It's a perfect storm of wood degradation.

I will layer the marine tex up in several layers over several days. My question is this -- since the door jam is vertical, I want to create a dam to hold the marine tex in place while it drys. I am thinking of using a board covered with wax paper so it will be easily removable.

Anyone have any suggestions, hints, or concerns aboout such an approach? I've used marine tex before with great results (including patching a teak rail that some joker smacked into years ago in the Berkeley Marina. Great stuff.

Thanks!

Matt

 

[Captains Cat]

Matt, not sure but would the West Systems stuff you use to increase the consistency of the epoxy work with Marine Tex? If not, why not just use the West Systems stuff and thicken it up until it gets like you want it to stick it in place?

Charlie

 

[Sea Wolf]

I sounds fine to me Matt!

The wood block/dam/mold approach with wax paper for mold release sounds fine. I've used it on sail and power boats many times.

As you well know, the closer you can approximate the finished shape withe the mold, there better off you will be, as hardened Marine-Tex is very hard and difficult to sand, or re-shape.

I hope the Marine-Tex bonds tightly to the old wood. If it's too soft or splits easily, you might drive screws down into it, leaving the heads just below the finished height to form anchors for the Marine-Tex to get ahold of firmly.

If the wood is really marginal, you might consider ripping out that piece and replacing it with solid plastic facia board or molding that won't ever rot again. This can be bought at most home Depot and Lowe's Stores. You will probably have to machine it down to the right dimensions from the closest size available.

Good Luck!

Joe. :teeth :thup

 

[thataway]

You will have to wash and sand the Marine Tex between applications--there are amines which come to the surface as in any epoxy. The wax paper will work--it may stick slightly, but easily sanded off.

Epoxies are subject to UV detiorration--Marine Tex is no exception-it will yellow to some degree with sun exposure. Best if any epoxy is painted after application

I use West Systems epoxy, with medium density filler, and enough Cabosil filler to mike it thick. Since the Marine Tex is already thick, I am not sure how well the Cabosil will mix in. It is just fumed silica, so it should work as a thickener.

When working on wood, I roughen up the surface and put a coat of liquid epoxy on first, then while it is still wet, put on the thickened coat. This allows penetration of the wood by epoxy so it adheres well.

 

[Tortuga]

In the end I bought a quart of Evercoat Formula 27 -- which is a polyester filler. I couldn't bring myself to pay the much higher cost of either the marine tex or west system. But, for the use, I think it will work just fine. It'll be painted with a couple of coats of paint as well so it will have a good barrier. It'll certainly be stronger than the doug fir of the door jam.

Thanks for the suggestions. I'd rather be working on the boat...

Matt