Soft ply ??? What to do...

[Touchwood]

Hi there,

My near 50 year Hartley 16 has a glass over ply hull.

Some of the ply not far from the centreboard is quit soft. I can scratch it away with a fingernail, causing a small hole which I can easily puncture from the underside with a sharp tool.

I plan to re-skin the entire hull next winter, but I am currently readying the boat for the upcoming summer, and would like to get some sailing out of it in the coming months.

Is applying a layer a fibreglass on the inside of the hull in the affected places a suitable option to prevent sinking in the short term ?? |;)

Thanks, Marty.

[john welsford]

Only if you are a good swimmer.

I suggest cutting a hole in the bottom back to solid wood, cutting a filler piece to closely fit the hole and a backing piece that should be a good 30mm larger ( minimum, more is better) all round than the hole then glue and screw the lot into place. Fill and paint the outside.

John Welsford

[Touchwood]

Thanks John.

Wondering, if its the original ply, built in 1964 - did they have marine ply back then ?

Its about 5mm thick at the most, fibrous, dry & soft - and doesnt appear to have layers like the ply I know.

??

[kc8pql]

Thanks John.

Wondering, if its the original ply, built in 1964 - did they have marine ply back then ?

Its about 5mm thick at the most, fibrous, dry & soft - and doesnt appear to have layers like the ply I know.

??
Yes, they did have marine ply, and was generally much better quality than today.
If there are no plys, it's not plywood. Could it be strip planked solid wood?

[john welsford]

Yes there was marine ply in those days, and some, only some, of the plywood was better than some you'll see today. I was building boats then, albiet small and simple but recall being able to buy New Zealand Kauri plywood which was amazing stuff.
But the glue is better today, more consistent and the technology and process control methods in the plywood factories is much improved. The thing that has changed is that the beautiful old growth forests are almost gone so the wood used in most plywood is not as good.

John Welsford

[kc8pql]

The thing that has changed is that the beautiful old growth forests are almost gone so the wood used in most plywood is not as good.

...which is kinda what plywood is all about. I built my first plywood boat in 1960. Bruynzeel Regina Mahogany ply. Wonderful stuff.