Making a locker top/seat

[lesweeks]

I’ve ‘inherited’ a couple of 1¼” Iroko lab bench tops which I’m going to use to make the cockpit lockers. My question is what adhesive to use for the tops/seats. My plan is to put an end clamp on each side with double tenons, wedged, in the middle so that any expansion will be equally spread across the board and so that the clamp cannot fall off. For much of the work on my restoration project I’ve used epoxy, but will this be too hard for this task? Should I go for something with a bit more ‘give’ to accommodate a bit of movement? Or, will whatever adhesive I use break down in time? Does anyone have any suggestions?

 

[joliette]

I’ve ‘inherited’ a couple of 1¼” Iroko lab bench tops which I’m going to use to make the cockpit lockers. My question is what adhesive to use for the tops/seats. My plan is to put an end clamp on each side with double tenons, wedged, in the middle so that any expansion will be equally spread across the board and so that the clamp cannot fall off. For much of the work on my restoration project I’ve used epoxy, but will this be too hard for this task? Should I go for something with a bit more ‘give’ to accommodate a bit of movement? Or, will whatever adhesive I use break down in time? Does anyone have any suggestions?

That is quite a sophisicated solution and probably not one that I would contemplate myself, in the interests of keeping things simple to construct, yet robust. Have you considered giving Bolcatan a try?

 

[nickd]

I have been using gorilla glue around the boat with excellent results
including laminating a new tiller, and scarfing in bits of teak

http://www.screwfix.com/prods/99386...Adhesives/High-Performance/Gorilla-Glue-275mm

Definitely worth a look

 

[Tranona]

Think your method is way OTT. Iroko is very stable (once it is cut) and you could just put the caps on with epoxy, although for alignment dowels or even wood screws plugged would be useful. As the joint is not taking any load a polyurethane glue such as Balcaton would be more than adequate. I glued up the Iroko frame of a hatch garage with Balcaton and its been out in the open now for 10 years with no failure of the glue.

 

[nealeb]

Think your method is way OTT. Iroko is very stable (once it is cut)

Would you like to come and tell the iroko locker lids on my boat that? They seem to have a mind of their own!

Mine are 12-15" wide, made of edge-glued panels around 5/8" thick. There's a strip along the front to form a lip but it doesn't seem to provide much anti-warp stiffness. I am seriously thinking of replacing them with marine ply panels, topped and edged with strips of iroko.

That's not proper "classic" boat thinking, I know, but it tells me that I wouldn't want to put cap strips on as shown in that excellent diagram. Iroko is durable enough that with a few coats of something to protect it, end grain is not really a weak point as it is with some timbers. Suppose it depends if you want something workboat-like, or "proper yacht"

 

[Tranona]

True it can warp when it is first cut because of curly grain, but usually atys stble once it is cut. Think your problem is the section you don't say how wide they are, but 5/8" is very thin - the OPs is 1 1/4" which is much more appropriate for locker lids.

Depending on the unsupported area, you can go down to 1/2" with ply, but even that will need strengthening battens if not well supported around th perimeter and a stiffening lip at the edge.

 

[nealeb]

I'm talking cockpit locker lids on a 28' gaffer - and even by my boat's scantling standards, 1 1/4" would be pretty heavy! But you're quite right - when I look at them what I have is pretty thin for the width. A 12-15" board only 5/8" or so thick is asking a lot from the wood stability point of view, and the problem is that now a couple of them have started to warp, I get heavy rain getting into the lockers.

I have facilities for wood machining, though, and I reckon that ply with "teak decking" style strips glued on top (which would match the sliding hatch cover) and some custom mouldings, all in iroko, to give a good finish round the edges would probably do the job nicely.

Maybe this will turn into this winter's project

 

[Tranona]

That is exactly how my locker lids are made. You can get 2.6mm teak veneers from Robbins which, when cut into strips and set in Sika really look the biz. Or you can use the West method bedding in thickened resin and grouted with black pgmented thickened resin.

 

[joliette]

That is exactly how my locker lids are made. You can get 2.6mm teak veneers from Robbins which, when cut into strips and set in Sika really look the biz. Or you can use the West method bedding in thickened resin and grouted with black pgmented thickened resin.

I'd cut that 1 1/4" iroko down to 1/4" thick strips with a table saw, plane to a good finish on one side and bond them to 1/2" marine ply with Bolcotan, leaving a 1/4" caulking gap between each strip.
I made the sole boards for my Settimo Velo like this: http://www.facebook.com/#!/group.php?gid=179427293999

 

[Timbow]

Les, your approach is perfectly sound. In particular don't listen to these guys suggesting plywood (unless this is a 'modern' classic) because restoration means using the right materials and plywood in the cockpit of an old boat will be a bit bleugh.

If you want to simplify the job then forget the tenons and cut your tongue and groove dovetailed with a router and maybe leave the joint unglued with just a stainless nail in the middle. If you want to glue the only adhesive which will allow creeping of a joint like that is PVA.

Tim W

 

[lesweeks]

Thanks!

Thanks for the thoughts and suggestions.
I agree that the timber is a little on the heavy side and maybe two tenons excessive- in fact I've now machined it down to just over the inch & I'll have just one tenon - but it was free and basically perfect for the task and I've got enough of it to make all the cockpit 'furniture'. If when the tops are completed they feel a bit too heavy I might use the router on the underside to lighten them up a bit. Frankly, I'm not too bothered about weight in the boat; it'll be whether they work well that will interest me.
As far as the gluing is concerned I'm still in two minds between polyurethane and PVA - I suspect that whatever I use, the glue line will give in a few years (or less!). Maybe I'll do port side polyurethane and starboard PVA.