Pedestal not very solid, cockpit sole flexing?!?

[Dufour4800-175]

Hello,

Im the owner of a Dufour 4800 1983 and I remarked that the steering pedestal was not very solid, im able to shake it quiet a bit without putting much strenght. I remark that the cockpit sole seem to bend a little when pushing on the pedestal on one side or another. The cockpit sole is not soft however and sound full when impacted (does not sound rotten). There are no stress marks or cracks on the fibreglass. When I use a humidity meter i read very high level of moisture in the cockpit sole. The question that I have is should i rebuild the sold (re-core it) or should i only install a reinforcement stainless plate from under the sole?


Thanks for your advices!
Alex

[neilpride]

You got rotten core , is up to you, but using a ss as backing plate maybe stiff the area in question, but sooner or later you need to do a proper job, recore the cockpit sole.... the problem is some builders cut the hole to fit the pedestal and dont seal the core, water with time leak under the pedestal and well , just figurate...

[Dufour4800-175]

All right... Would you attempt to do such a job from under to preserve the finish and anti slip or would you simply cut from top?

Thanks for your reply!
Alex

[neilpride]

No idea what you have under the cockpit sole, engine? tanks? bulkheads?
And how wide and big is the area in question? if the cockpit floor is deflecting if you move the pedestal i guess the rotten area is big.
Could be a good idea start to drilling pilot holes under the floor looking for dry core...and determine the rotten section. Replacing a huge core area under the laminate could be a pain in the ass, there is some Vacum techniques but all the dust and !!!!! depend if you want to keep the original gelcoat in top, in your shoes i do the job from top, and later choose a gelcoat finish or non skid topcoat, is easy do it from the top.

[Mike Vogdes]

Much easier from the top.. Not a easy job if have no experience with fiberglass, epoxy and coring materials, you would be wise to get some help or hire the job to a pro.

[Krogensailor]

I would reenforce the btm with a thick glass backing plate, 1/4 to 3/8" epoxed in place. Then add stringers fore and aft and side to side glassed in place. Would then cut the top layer of glass,(hope you don't have a teak sole), replace the core with foam. Glass with db170. If you had teak, I would consider the vinyl teak lookalike material. Normally I have been too traditional for this sort of thing. But the boat I'm restoring came with the cockpit covered in this material. I thought it was teak until I looked closer. Scrubbed up well, never wears out. A little pricey, but anything that cuts maintenance is a friend of mine.

[RaymondR]

If the only holes that have been drilled through the cockpit floor are those where the pedestal is bolted down these are probably the culprits in allowing water into the core and any subsequent rot.

There is probably a fairly decent sized hole under the pedestal where the tiller cables/shafts pass through the cockpit sole.

I would remove the pedestal and see if you can ascertain the extent of the problem by digging out the softened material via the large hole.

If the extent of the soft material is not to large you may get away with epoxying a number of plywood pieces under the cockpit sole's outer skin and then just re-glassing the under deck.

[Dufour4800-175]

Thank you all for your advices, from what I see, i might as well do it from the top! Under the sole is the engine bay and i have not much headspace above the engine... I would be crawling in and out and it would probably be a pain!!! Im gonna start by taking the pedestal down, and investigate the extent/nature of the damage. Since the humidity meter was reading extreme humidity all around the sole, ill probably end up tearing it all appart. There is no teak so im lucky!! Ill keep you posted on what i discover as soon as I make more progress!
Thanks
Alex

[Cheechako]

I've done the whole V berth in a 44 footer from below... wasnt really that hard. Basically on my knees most the time though.. If you have more space and a big tarp, you could do it from below...... although repainting a cockpit sole.... (if you do it from above) is a lot easier than painting the whole deck or forward of the cabin... as I would have had to. You could investigate from below, because it may be quite likely that the rotten core is just around the pedestal area... piece of cake if that's the case.... I would core it with good ply in lieu of balsa below the pedestal.

[Dufour4800-175]

Originally Posted by Cheechako

I've done the whole V berth in a 44 footer from below... wasnt really that hard. Basically on my knees most the time though.. If you have more space and a big tarp, you could do it from below...... although repainting a cockpit sole.... (if you do it from above) is a lot easier than painting the whole deck or forward of the cabin... as I would have had to. You could investigate from below, because it may be quite likely that the rotten core is just around the pedestal area... piece of cake if that's the case.... I would core it with good ply in lieu of balsa below the pedestal.

Thanks for the input,

And what about plastic coring materials or foams?

[Cheechako]

well , of course they are all fine as is balsa, but with the bolts compressing the sandwich, I'd opt for the ply, dril the holes and paint epoxy in there before resetting the pedestal. If core I would make the epoxy inserts at each hole.

[neilpride]

I dont think the core section is just at the pedestal area, most probably the whole cockpit sole,but is easy to see from underneath, and dont make any sense to replace the core with something prone to rot again, ply and balsa could be fine , but you need to make it watertight 100% , foam and balsa are easy to cut and make curves , and in the pedestal area you can choose something stronger,in any case the pedestal got a lot of abuse, people grabing the wheel , holding here , there...