glass fibre reinforced filler -which one ?

[markpageant]

I'm putting a backing plate in to support the outboard bracket and strengthen the transom. Anyone reccomend a suitable filler and supplier. It will have to set hard, shrink very little, be strong and rigid and capable of being applied in a thickness up to 2cm.

 

[OGITD]

I don't know yet! of any reason why not to use P40.

Although when I fitted my Transom Bracket I used a 1 ½ foot square 4mm 316 stainless internal plate with ample Sikaflex, and an Oak pad with routed edge for the external mount also with ample Sikaflex trimmed from around the edges once set.

 

[damo]

P40 gets used a lot on my boat! Don't go anywhere near a chandlery for grp stuff /forums/images/graemlins/smile.gif

 

[oldsaltoz]

You can get Micro fibres from any boat builder or fibreglass outlet, an alternative is off cuts of fibreglass cut into very small bits.

If you use an epoxy resin and micro fibres you can cut part way through the sheet of ply allowing it to bend, this will reduce the amount of resin required.

Keep in mind if you get this wrong it will be right mess trying to strip it and redo. Cutting costs can lead to more work if not failures, just not worth the risk.

Avagoodweekend......

 

[homa]

P38 from a car accessory shop

 

[samwise]

Is P38/40 OK for underwater filling or do you have to bite the bullet and pay for Watertite or similar? I have quite a bit of filling to do on our keel and would need a mortgage to buy the Watertite volume I may need!

 

[Tranona]

Know you asked for advice on how to strengthen your transom. However, not sure levelling the curve with filler is the best way. A ply backing plate is required and you could make this by shaping say two 12mm panels laminated together to fit the curve and glassing in or using two 6mm thicknesses which will take the curve individually by bolting through the transom with you bracket bolts. Do the first one slightly larger and when it is bolted up using thickened epoxy, laminate the edges to the transom with glass and epoxy. when cured laminate the second one the same way. That will spread the load much better and avoid hard spots. Stuff like P38 is a filler, not structural.

 

[aquaplane]

I seem to recall being told that leaving the bits of filled bodywork on my old banger unprimed was asking for trouble. Car filler is porous and adsorbs water and swells so needs sealing with paint PDQ. Of course that's what most folk do so it's not an issue.

There will be folk who have had car filler on their boats for 40 years without problem I suppose, but life is like that.

I think I would be looking at working a piece of ply or wood to take the curve, it's not excessive on a Pagent is it.

 

[oldsaltoz]

[ QUOTE ]
Is P38/40 OK for underwater filling or do you have to bite the bullet and pay for Watertite or similar? I have quite a bit of filling to do on our keel and would need a mortgage to buy the Watertite volume I may need!

[/ QUOTE ]

P38 is a polyester filler, polesters are not recommended for underwater application nor as a glue.

See web page

 

[markpageant]

Thanks all, lots of advice.I think that between the fora I now have this cracked. 'laminating' relatively thin ply between thickened epoxy with regular, glas reinforced car bodyfiller for some of the deep voids, backd up by a meaty thick ply backing plate - al then flo coated in -seems to be the answer. Many thanks...

 

[damo]

I'd also suggest sealing the ply with epoxy before covering it, then epoxy to coat any drilled holes. Water always finds a way.....