Replacing Backing Plates

[europasailor]

The backing plate for my rudder fittings on my Hunter Europa looks as though it is rotten and needs replacing. It is encased in glassfibre which I can cut out, but the problem I have is what to do with the tube for the self draing cockpit which runs through the bottom of the backing plate. Would it be best to cut the pipe and reglass it when the new wood is fitted?
Has anybody any experience of this repair or one similar, I would like some reassurance before I attack the boat with an angle grinder.
I look forward to your replies with interest.

 

[ccscott49]

Could you not use an aluminium backing plate, with the crew holes tapped in it, it would solve your rot problem. But I cant understand why a piece of MARINE ply encased in polyester would have rotted in the first place? Don't know about the tube, but I would replace it with a copper tube, glassed in.

 

[Twister_Ken]

Cheap and cheerful???

Rather than replacing/rebuilding is it feasible just to reinforce by adding another pad, oversized compared to the current one, epoxied inside th etransom, over the existing arrangement. Then pull the old pintle & gudgeon fittings, drill through old and new pads, and refasten with longer through bolts. Belt and braces would be to drill though the transom at the corners of the new pad and bolt through there as well. Suitable sealants, etc.

 

[charles_reed]

Yes,
I'd agree - why the rot.

Sounds as tho' water got into it and the same thing will happen if you replace it.

I'd suggest finding that out before deciding on the exact material/method of replacement tho' the idea of using a tapped metal plate has many benefits.
Aluminium needs to be at least the same thickness as the bolt diameter to have an adequate thread - I'd prefer to use 316 or a piece of bronze (easier to work and far more corrosion resistant then stainless in anaerobic conditions)

 

[ccscott49]

Bronze would be belt, braces and a bit of string, but I thought plate might be a bit difficult to get hold of.

 

[oldsaltoz]

G'day Malcolm,

Sounds like water has got in thru the pintle bolt holes and rotted the timber.

To remove the old timber pad, just grind around the edge, most are not glued to the transom, avoid the temptation to prize it off with a lever, you Many crack the gelcoat on the outside.

Replacement should be 316 but make sure you apply a bedding mix behind the plate when fitting, and don't tighten it till after the bedding has gone off.

As for the drain pipe, most builders use PVC, the same as you have at home, the trick to getting fibreglass to stick to it is to burn it with a torch or gas, use a lot of heat but for a very short burst, you only want to get the heat into the surface , not melt the pipe, very small dark beads will form when enough heat has been applied.

If you can cut the pipe without disturbing the fibreglassed end, you will save time and expense, use standard PVC fittings to re-join it after the plate is in place.

I Hope this helps.

Avagreatchristmas Old Salt Oz /forums/images/icons/cool.gif