Deck Matrix

[two stroke mick]

I want to put in a deck matrix to allow for removal jockey seat, bench seat bottle rack etc. I plan on using 4 or 5mm thick Stainless steel plate. Two plates each 100mm wide by 800mm long which will be joined togeter with three 50 mm Stainless stringers. This unit to have 7 blind M 8 nuts on each plate i.e. 14 blind nuts in total. The unit to be sikaflexed and screwed down at 100mm C/C. I then intend to cover the unit with 4-6 layers of 300mm CSM and then flow coat the deck. This arrangement will give me 8 bolts for a single jockey (4 each side) or 12 bolts for a Double jockey and 6 bolts for a bench seat. I intend to use bolts like this A2 Stainless Metric Studding Connector Nuts (DIN 6334) on the under side of the plate with the ends blanked off.

A plan view of the deck matrix shown below





Your thoughs on this arrangement please. The last thing I want is a jockey seat to come away from the deck. I think that this may have been the failure mechasim that caused the failure of the jockey seat on MustRibs gemini in the RI 2013 event earlier. If I am mistaken Must rib then I am sorry in advance

TSM

[Poly]

Will it ever be used with just an open deck? it sounds like a trip hazard to me. Is the deck ply, 'solid' grp, or got a core?

[two stroke mick]

deck is grp on plywood under which there is some kind of foam. The deck would be used as an open space for diving

[MustRib]

Your thoughs on this arrangement please. The last thing I want is a jockey seat to come away from the deck. I think that this may have been the failure mechasim that caused the failure of the jockey seat on MustRibs gemini in the RI 2013 event earlier. If I am mistaken Must rib then I am sorry in advance

TSM


TSM... nothing to apologise for.
Events all happened in a split second, but the boat was extremely on its beam, after the crest. I am pretty certain the seat parted company with the deck as a result of some big lardy bloke being sent sideways with a violent snapping motion as opposed to seat detachment being the reason I went sideways. The seat didnt have enough sideways motion to be ejected from the boat, and if I recall, the damage to the deck was more in line with a levering motion. Anyway, I wouldn't skimp on the pate as regards the lay up. I think my seat was subjected to an extreme force, and as Poly pointed out, seats detaching from the floor in the circumstances is not unusual.
btw I cap the open ununsed big heads in the floor with a Hex dome head bolt, and these all but disappear into the Treadmaster, hardly standing proud of it at all.

[Poly]

Originally Posted by MustRib

I think my seat was subjected to an extreme force, and as Poly pointed out, seats detaching from the floor in the circumstances is not unusual.

I might well have said its not unheard of - it doesn't mean its right (of course even if the seat stays put it doesn't ensure that the helmsman/crew do too).

There have been a few threads on here in the past with people looking to put removable fixings in. Don't recall anyone going as complex as you are proposing. If the deck design supported it I'd have though a small flush hatch to put bolts in from underneath was the 'best'.

Have a look at: http://www.rib.net/forum/f8/removabl...tml#post564942
http://www.rib.net/forum/f8/name-nee...ngs-31839.html
http://www.rib.net/forum/f8/fitting-...tml#post195885
http://www.rib.net/forum/f8/diy-jock...html#post19814

[Searider]

My old 4m Searider Deluxe had blind fastenings embedded in the floor for securing the seats to.
There were also some blanked off ones, presumably for fitting a console if the boat were specd as a rescue version.

Poly, I'm not sure having hatches in the deck to allow through bolting will be practical.

[ShinyShoe]

Originally Posted by Searider

Poly, I'm not sure having hatches in the deck to allow through bolting will be practical.

4" inspection hatch like this: DINGHY/YACHT Inspection hatch - WHITE | eBay

In the middle of the seat/console (provided you can get to the middle of the seat/console) - would have no traffic so very little abuse) and should let you get in to put the nuts and big washers on...

But does depend what the structure under the deck is like.

They are pretty robust (there are some that are a bit more flexible) but the one I linked to is "solid". They keep water out well on sailing dinghies so would be happy with the seal on a SR4 deck.

[Poly]

I was actually thinking something that was genuinely flush and in steel - but I've just looked at the price

There is no benefit to a slightly raised hatch - it would need to be recessed to be flush; I'm thinking tripping, stubbed toes, comfortable under bare foot - when the seat / bottle rack is not fitted.

a SR4 deck

its for a valiant.

[ShinyShoe]

Originally Posted by Poly

There is no benefit to a slightly raised hatch - it would need to be recessed to be flush; I'm thinking tripping, stubbed toes, comfortable under bare foot - when the seat / bottle rack is not fitted.

Hadn't really understood. (shut it!) I took it the desire was just to have some nuts on the underside, not to be changing boat config.

its for a valiant.

Whatever

[two stroke mick]

Placed the order for the ss deck matrix. cost circa 450 euro. lets see if the experiment works.

[two stroke mick]

I have as of today taken delivery of my deck matrix. Now it is time to start how to drill a hole thread. The plan is to drill out deck to recess the nuts, Screw and sika flex to the deck. The glass the unit in place and then flow coat the deck.
TSM

[two stroke mick]

Drilled out the deck to accept the deck matrix this weekend. No going back now. This is turning out to be a bigger job than I though
TSM

[two stroke mick]

Sanded the deck, cleased with thinners used a tuble of sikaflex 291 i in the cold. Then screwed the deck matrix into place. Next job to glass over the stainless unit and flow coat the deck. Belt and braces job.

[Festinghouse]

looking good, though youre giving me ideas i could well do without!

[Pikey Dave]

Originally Posted by two stroke mick

Sanded the deck, cleased with thinners used a tuble of sikaflex 291 i in the cold. Then screwed the deck matrix into place. Next job to glass over the stainless unit and flow coat the deck. Belt and braces job.

How are you going to protect the threaded holes from the GRP/flowcoat?

[two stroke mick]

Pikey

I plan to use 8mm treaded bar. cut into 50mm lenghts. Screw in the treathed bar and glass around the treathed bar. When finished use visegrip to get purchase on the bar and tread the bar out. I dont know if it will work. I will tell you in a few weeks time.

TSM

[tumnus]

Originally Posted by two stroke mick

Pikey

I plan to use 8mm treaded bar. cut into 50mm lenghts. Screw in the treathed bar and glass around the treathed bar. When finished use visegrip to get purchase on the bar and tread the bar out. I dont know if it will work. I will tell you in a few weeks time.

TSM

Why not use a long bolt instead of threaded bar? Surely something wih a head on it would give you better purchase to extract it using a socket set or driver , when you have finished glassing.

[Chris Caton]

socket head cap screw will have a relatively small head, but you can use a allen key to make removal easy afterwards

[Pikey Dave]

Originally Posted by Chris Caton

socket head cap screw will have a relatively small head, but you can use a allen key to make removal easy afterwards

+1, put some Copperslip on the threads too, if one picks up you're shagged. I'm guessing that the GRP will need a bit of fettling around the holes when you unscrew whatever you use to protect the holes.

[Poly]

Originally Posted by Pikey Dave

+1, put some Copperslip on the threads too, if one picks up you're shagged. I'm guessing that the GRP will need a bit of fettling around the holes when you unscrew whatever you use to protect the holes.

would vaseline or silicone grease be better than copper-slip? - in that cleaning copper-slip off the internal threads will be a PITA but you don't want to leave a smear on there to accelerate dissimilar metal corrosion when the final assembly is done?