Ply Repair - Guidance required

[ghoti]

I have been mulling this for a few weeks with no result so I now approach the experts...

My fuel bay is ply sheathed in glass which was badly delaminated. It appears a single pack primer was used under the glass which probably did not help. I have cut back the rotted section to get a scale of the problem but I am lost on the best solution.



My thoughts on options;

1) construct a full 12:1 scarf in a a new piece
2) clean up edges and butt in a new piece with a block behind.
3) clean up edges and butt in a new piece

I have started constructing a patch a few times but I am not sure my skills are up to it. Scarfing on a workbench is one thing but in situ like this is causing me some problems. I have tried a few practice pieces and the results are pretty rough and ready.

Obviously I want a fairly strong result as the bay will have 80kg of fuel bouncing around.

Any input? are options 2 or 3 that inferior? methods of doing a decent scarf in place?

Thanks!
Alex

[Ron Williamson]

If there is nothing critical behind it,I wouldn't scarf at all,just block behind it,then glue and screw new stuff to the blocking.
A small grinder and a big rasp make fitting easier.
R

[skaraborgcraft]

This is one time when i would suggest using epoxy as a glue/ filler. Butt in a fresh piece.Dont over think it. Easy repair

[ghoti]

Thanks,

I was worrying about sheer loads but ill go for it and butt it from behind (nothing special behind it).

This place is like dutch courage without the booze.

Alex,

[chuckt]

I haven't previously heard of the phrase "dutch courage." "A fortifying drink taken before a challenging task."

[Brian Palmer]

I would make sure you got rid of all the moldy, suspect wood and use a butt with a block behind it. I've used that approach in several places throughout my boat. No need to scarf unless you can see both sides, or the piece will be subject to bending loads.

Brian