Next Question - To Goop or not to Goop?

[Stemar]

Thanks for your patience with all my questions, everyone. I'm afraid there'll probably be a good few more before Jazzcat's up to scratch.

Here's the next couple. The hulls stick out about 18" beyond the "transom" and the gap is filled with a stainless steel frame with wooden slats, which are in need of replacement. I've found some meranti at a sensible price that's sold as garden chair slats - way thicker and stronger than I need, but I can live with strong.

Question 1: Should I do anything apart from give the slats a few coats of patio furniture oil before screwing them on?

Question 2: The old slats had some sort of goop between them and the frame. Is this a good idea, or is my suspicion that it was just a moisture trap likely to be correct?

 

[Laminar Flow]

I would not use meranti it is, quite frankly, not very rot proof.

Go for something like iroko, or purple heart, both of which are cheaper than teak. Another cheap choice would be Ipe, often used for exterior wood decking. It is rather dense & heavy, as in it doesn't float, if you feel like ballasting the decks of your cat. I made my cockpit gratings out of the stuff and it is pretty much impervious to rot & bugs. I also used some for the slatting on our new SS bowsprit - I did not bother with any goop.

Oiling doesn't last much longer than the first few moments of ecstasy after installation, unless you are willing to give it a new rub down every morning or so.

 

[penfold]

If weight isn't an issue GRP grating would be a durable if somewhat utilitarian alternative to the expense of hardwood.

 

[Tranona]

Agree, meranti not really a good choice. Warps easily and rots quickly. However if it is thick and well supported coat it with a good woodstain - I would use International Woodskin 'cos I have some and it would be good for the job and it should last a few years. Oiling of wood for use externally in an exposed position like that is a complete waste of time. Presumably you will be bolting through the wood and frame so worth putting some butyl ot polysulphide sealer around the holes and where the wood rests on the frame to stop water getting under the coating.

 

[Mister E]

On ours I just used house decking boards from Jewsons for the same thing.

 

[Rappey]

I have iroko on my cockpit floor uncoated and at 38 years old its still in excellent condition..
Sydenhams on the meon valley road can sell you sawn hardwood really cheap, prepared nearly increases the cost 3 fold..
I have a wood thicknesser if that helps..

 

[Laminar Flow]

On ours I just used house decking boards from Jewsons for the same thing.

Yes, which are usually made from Ipe. They tend to come in two varieties: smooth (planed) or with one side grooved. Ipe can warp quite impressively, but, as in decking applications, when fastened every 16" it tends to stay in place.