Deck seam paying on traditional laid deck?

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yorkie_chris

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Hi

Need to re caulk the deck on helene. It is mahogany 2.5'' thick I think.

Caulking then paying... What is your preferred poison and why?

I am leaning towards old school marine glue due to ease of repair and it isn't too expensive.

Tempted to try using hot melt roofing adhesive as that's lots cheaper still.

Not fussed on appearance as its a working deck but want it dry
 
I used a Sikaflex product but it was only for a small area. A cheaper material that I would use next time is CT1 but your idea of roofing adhesive is probably much cheaper.

For getting the old stuff out, Fein make a special blade for their Multimaster that works well.
 
Are the decks really mahogany? That would be an unusual use of mahogany as decks are usually laid in a oil/resin rich timber such as teak, pitch pine or even larch. However, I have found using TDS Teak Deck Caulking to be easier and more successful than the Sika product for deck seams. Cotton is still my choice driven caulking.
Good luck!
 
Not 100% sure it's mahogany but it doesn't seem like teak as there are a few bits of rot (1966 built). Hardwood supplier thought Brazil mahogany

Jeffreys glue is looking like preference at moment
 
I agree with Ben's suggestion, it looks like iroko to me. That would be in keeping with the odd area of rot as it is not as durable as teak.
 
End grain photo almost definitely iroko 95% positive. Avoid the sanding dust, quite an irritant and long term carsonogenic for some. Generally quite durable so long as sapwood is avoided although the quality does vary considerably, some is very heavy with silica inclusions and hard to machine, some very light and much softer.
 
If its red & exudes resin it wont be iroko, it sounds awfully like Keruing, this commonly has resin pockets & end grain is similar. Usually used for lorry backs not for boat decks
 
Must admit that if the sample is more red than brown then Kerruing is a possibility . The end gain of both does have some similarity although the photo needs to be a bit sharper to be totally accurate. Iroko has short chains of pores surrounded by a white border. Kerruing has mostly single pores surrounded by white border. As previously said Kerruing is not a common boatbuilding timber. Very unwieldy and difficult to finish with no real beauty.
 
In the end I guess it is not really that important, the treatment and repair is the same whatever, although you might be better off repairing failed areas with iroko despite it being a different colour, it will all weather down to make no difference. Your deck is definitely a hardwood so you would not use a softwood like larch to repair it though as the stability (shrinking and expanding) is different.
 
Probably not so important as it would be with teak as teak does have alternate hard and soft areas between the growth rings hence quarter sawn has the maximum areas of hard teak for a given width facing the surface of the deck minimising excessive wear ridging. Iroko is pretty much consistent with regard to surface hardness wherever & however you cut it as the growth rings are not prominent.
 
johnlilley said:
Probably not so important as it would be with teak as teak does have alternate hard and soft areas between the growth rings hence quarter sawn has the maximum areas of hard teak for a given width facing the surface of the deck minimising excessive wear ridging. Iroko is pretty much consistent with regard to surface hardness wherever & however you cut it as the growth rings are not prominent.
Click to expand...

That would make getting hold of the timber a lot easier for sure.

I thought the preference for quarter sawn was more because there was more growth/shrinkage tangentially than radially.
 
That is true with softwoods but teak & iroko are very stable and the difference in a 2.5" wide board would be negligible. As previously said, the wear factor in plain sawn teak is more important than in iroko. That is also why it is required to have a flexible seam filler/sealant between the boards. The other reason quarter sawn is used is that it is easier to bend on edge if the deck is a swept deck. Straight run should not be any problem.
 
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The boards are 4" wide, 2.5" thick, so a little more expansion, but not much.
Everything on board is bloody massive as there were a pair of rope drums bolted straight to deck, these weighed nearly 3.5 ton without the (lead weighted) seine rope.

Thanks for the advice, now I just need to grow a set and chop a big hole in my boat...
 
The next question is what type of joint to use where I let pieces in to the deck.

the joints are mostly going to be over deck beams, I'm not sure if the extra work of a nibbed scarf joint will be worth the effort compared to butt joints as they will be harder to caulk as well
 
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