Covering bulkhead - hull joints

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Graham_Wright

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Recommendations require glassing to be applied in diminishing widths when joining bulkheads to the hull. This is for stress distribution.

Unfortunately, the glass overlapping your beautiful teak faced ply is not cosmetically acceptable.

The solution could be to buy 12/15 mm thick planks and profile out cover strips to hide the offending glass.

This is not a cheap solution!

Anyone have any other suggestions please?
 
Graham_Wright said:
Recommendations require glassing to be applied in diminishing widths when joining bulkheads to the hull. This is for stress distribution.

Unfortunately, the glass overlapping your beautiful teak faced ply is not cosmetically acceptable.

The solution could be to buy 12/15 mm thick planks and profile out cover strips to hide the offending glass.

This is not a cheap solution!

Anyone have any other suggestions please?
Click to expand...

Bond in 12m/m ply & cover in 3m/m teak faced ply ( inc over the GRP )fixed with contact adhesive is the normal method ( well used to be )
 
Graham_Wright said:
Recommendations require glassing to be applied in diminishing widths when joining bulkheads to the hull. This is for stress distribution.
Click to expand...

Pedantic point: in such situations you should apply the cloth/tape/mat in increasing widths. That means that each layer is independently glued down. If you do it in decreasing widths the joint depends entirely on the bonding of the first layer to the substrate.
 
The plywood teak facing 'should have' been roughly removed when bonding the bulkhead in, so the tabbing strips of glass bond to the plywoods cores and at the same time project less thickness once complete, making for any teak cover strips ( which can look very posh if done neatly) an easier job to do..

An alternative for the OP might be to consider bonding teak veneer directly to the glass using a epoxy filler goopy 'paste' then filleting any remaining visible step or edge ( or even running a edge strip around the step) but this requires considerable dexterity to make it look natural and not 'unexpected' when viewed...you would have to decide on the grain and joint layout too..

As SM says, mainstream construction has been streamlined using pre-alignment techniques and modern mastics these days
 
sailorman said:
I was not talking of veneer but 3m/m teak face ply.
this was the usual method of covering bonded in bulkheads that would be seen
Click to expand...

I think I misunderstood. The bulkhead was bonded in (with diminishing i.e. outwards to inwards!) a long time ago.

So what you suggest is 3mm faced ply over the joint (not over 12mm and 3mm).. That is the only solution I have considered and you have reinforced my thoughts. It still leaves a projecting edge though. Dredging my patience, I could recess the back where the glass is so that it would sit down better where it meets the bulkhead.
 
Graham_Wright said:
I think I misunderstood. The bulkhead was bonded in (with diminishing i.e. outwards to inwards!) a long time ago.

So what you suggest is 3mm faced ply over the joint (not over 12mm and 3mm).. That is the only solution I have considered and you have reinforced my thoughts. It still leaves a projecting edge though. Dredging my patience, I could recess the back where the glass is so that it would sit down better where it meets the bulkhead.
Click to expand...

12m/m bulkhd bonded in totally faced with 3 m/m teak faced ply right out the hull, the facing ply will bend over the GRP web
 
sailorman said:
As if all done at the same time it is all one lay-up of GRP
Click to expand...

The resin is continuous, but overlapping the layers provides better stress flow through the glass.

What's wrong with glassing in the bulkhead (the right way or the wrong way!) and then putting a wooden cover over the join, as in my last boat (Westerly), my current boat (Northshore Mouldings) and just about every other structural bulkhead I have ever seen?
 
JumbleDuck said:
The resin is continuous, but overlapping the layers provides better stress flow through the glass.
Click to expand...

I think Sailorman's point is that once the resin goes on and the binder dissolves, and especially once you've belaboured it with a ridged metal roller, the glass strands are all combined into one mass rather than remaining as separate layers. Dunno if he's right, but that's how I understood his post.

Pete
 
JumbleDuck said:
The resin is continuous, but overlapping the layers provides better stress flow through the glass.

What's wrong with glassing in the bulkhead (the right way or the wrong way!) and then putting a wooden cover over the join, as in my last boat (Westerly), my current boat (Northshore Mouldings) and just about every other structural bulkhead I have ever seen?
Click to expand...
None at all, but overlaying with ply masks the GRP flange rather that accentuate it
 
prv said:
I think Sailorman's point is that once the resin goes on and the binder dissolves, and especially once you've belaboured it with a ridged metal roller, the glass strands are all combined into one mass rather than remaining as separate layers. Dunno if he's right, but that's how I understood his post.
Click to expand...

The resin is certainly combined but, particularly if you're using cloth or tape, there is a risk of ending up with layers of GRP separated by layers of pure P. It probably doesn't make a huge amount of difference, but on the other hand it really isn't any more work to spread the glass outwards, so why not?
 
sailorman said:
None at all, but overlaying with ply masks the GRP flange rather that accentuate it
Click to expand...

True, but I'm not sure that there really is an alternative. The problem with sticking teak veneer on top is, I think, that you'd end up with something teak coloured but clearly not teak. To look right it would have to look like a proper teak strip, in which case you might as well use a proper teak strip and be done with it.
 
JumbleDuck said:
True, but I'm not sure that there really is an alternative. The problem with sticking teak veneer on top is, I think, that you'd end up with something teak coloured but clearly not teak. To look right it would have to look like a proper teak strip, in which case you might as well use a proper teak strip and be done with it.
Click to expand...
What do you not understand about 3m/m teak FACED PLY bonded to the whole ( non faced ) bulkhd inc over the GRP flange as well
 
sailorman said:
What do you not understand about 3m/m teak FACED PLY bonded to the whole ( non faced ) bulkhd inc over the GRP flange as well
Click to expand...

I thought the OP already had a teak faced bulkhead and wanted to hide the bonding round it. In which case, sticking a sheet of ply over the whole thing seems a bit overkilly. Anyway, I was responding to the veneer suggestion (#8) and not to yours ...
 
JumbleDuck said:
True, but I'm not sure that there really is an alternative. The problem with sticking teak veneer on top is, I think, that you'd end up with something teak coloured but clearly not teak. To look right it would have to look like a proper teak strip, in which case you might as well use a proper teak strip and be done with it.
Click to expand...

Teak veneer is real teak! That's why it's called veneer and not plastic edging strip.
 
Now that the original poster has lost control of his thread and been elbowed aside, I'll chuck in my two-penn'orth.

Paint the whole bulkhead white, then the grp will be hardly noticeable.

Varnished ply is horrid anyway, you're better off without it. Like living inside a cigar box. :)
 
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