Flybridge Table Install

Looking at installing a settee and teak table as shown in this pic on the flybridge of my 1987 Grand Banks 42' with original but in good shape teak decks.

What is the proper way to install the table base like this on top of teak decks? Does the base have to be through bolted with a backing plate? That would require temp removal of the headliner which I am not very excited about. I don't know the thickness or exact make up of the cabin top. Believe it is plywood sandwiched with fiberglass but don't know how thick. Any comments/hints appreciated.

Second, what fastening is needed for the settee? Through bolt again or just screwed down to deck? I would think that the weight and shape would keep it pretty grounded with minimal fastenings or is that foolish thinking?

Any help/comments appreciated.

I would through bolt it in case someone fall against it while you are underway. I have not put a tabke in like that but I did add a seat on the flybridge. I used a Todd mounting ring to mount the seat base to the deck. It is a round aluminum ring that you bolt to the deck and then screw the seat base to the ring. It has about a 3” hole in the middle. I used a hole saw to cut a 3” hole in the fiberglass deck. Then I slid 6 3/8” thick aluminum plates that I had tapped for 1/4 X 20 bolts in through the hole in the fiberglass. Bolted the mounting ring to the deck. Then screwed the base of the seat to the mounting ring. That way I did not have to drop the headliner in the salon. I am not sure if your base would bolt to the Todd mounting ring but it might.

For most boats using a seat pedestal base that can raise and lower , and is perhaps 3-5 times as robust as a table base seems worth the effort and extra expense..

Thru bolt .

Thanks Dave/FF. A simple hole. Who knew? Never thought about that one. That's the answer. I do not have a table or settee at this point so getting a base that will match the Todd mounting ring will do the trick. Agree on a raising base and more substantial piece for the table. Better make sure I am certain of placement before taking a hole saw to my deck. Ouch. Not sure I have the nerve. On the settee, what options do I have for that? Same type of deal? Since the load is spread out more than a single post what is needed?

These sometimes come in handy.....

https://www.westmarine.com/buy/fasco-fasteners--stainless-steel-togglers--P013_390_003_520


But the Todd split ring assembly is nice too.

Thanks PS. don't know why I overthink pretty much everything about my boat. I've used toggles, hollow wall anchors, and the like 100 times around the house. Why I think a boat is different...haven't a clue. Except for those times when it is very different. Can you say electrical? I guess that's what gets me.

Why not just a folding table that can be put away when not wanted or moved around?

I thought about the toggle bolts, but I wanted something more robust. I tapped 3/8” aluminum and they each are about 1.5 X 3” to spread out the load. But I was doing a chair which probably has more of a load than a table.

Before you start drilling, you should make sure that the hole will not come out on top of a beam or support in the headliner. I take a couple of really powerful rare earth magnets. Tape one on top of the deck where you want to put the table. Go into the salon and move another magnet around the overhead. They will find each other so you will know where the table mount will be. Then push up on the headliner to see if it has some give and there is a bit of area open above the headliner. I had about 1/4 to 3/8” of open area between the fiberglass and the headliner plywood. Just enough to slide my 3/8” plates in around the edge of my hole in the deck. You don’t want to drill a hole in your deck and find out there isn’t any room for the backing plates...

An additional thought- if you're making holes in the deck and it's cored, you should pot the holes with thickened epoxy. Drill the hole in the deck and through the coring but don't penetrate the inside laminate. Cut the coring back with an allen wrench in a drill, vac out the debris, wet it out with plain unthickened epoxy then fill the cavity with thickened epoxy. When it cures, you can drill the hole for the fastener. The epoxy plug seals the coring so no water can enter the core when the bedding gives up. The plug also provides structural integrity to keep the through bolts from compressing and weakening the core. Any penetration through a cored structure should be done similarly. Yes, it's a PITA, but it's the proper way to penetrate that structure.

Thanks Steve, will do. Have done that in the past although nothing as large as 3" hole. Right now I have found a couple of options for the base and table. Can't find anything close for a settee. Plenty of pontoon boat furniture but nothing that looks like my example pic above. Have the ability to build one from wood but don't want the weight or more wood to maintain. Enough already.

rochepoint said:

Why not just a folding table that can be put away when not wanted or moved around?

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Mike, thought about it and it is still an option but we thought something more permanent would be better with boat movement/rocking, etc. Maybe that's wrong but was our thinking. After last weekends experience when a 50'+ sportfish peeled out right off our port quarter and rocking us and 5 guests off our feet stability would seem to be a good attribute. Rare event (hopefully) but on our minds! Freestanding table would have been all over the place.

firstbase said:

Mike, thought about it and it is still an option but we thought something more permanent would be better with boat movement/rocking, etc. Maybe that's wrong but was our thinking. After last weekends experience when a 50'+ sportfish peeled out right off our port quarter and rocking us and 5 guests off our feet stability would seem to be a good attribute. Rare event (hopefully) but on our minds! Freestanding table would have been all over the place.

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Exactly why I would want it through bolted and backed up. Someone will grab onto the table and anything less will give way.

I just installed a Lagun table mount in my cockpit. The table top can rotate 360 degrees and that rotation point is on an arm that also rotates 360.

A very simple mount, more secure and more stable than the center pedestal we replaced. Superb quality. I could not be more pleased.

"Exactly why I would want it through bolted and backed up. Someone will grab onto the table and anything less will give way."

A table mount is a 3 ft long lever prying at its base every time its touched.

Install a mounting plate on the deck outside where its bolted as well as one inside to take the loads.

The outside mounting plate has the added advantage of raising the mounting bolts up from the deck, so they will only leak if the water in the deck is higher than the plate is thick.

This concept works well for any item that is not likely to be a toe breaker.

Thanks for the video on the rotating table leg. Not sure how I could get that to work for this install though as it is vertical....?

Before my OP I was thinking that if I couldn't through bolt it I wouldn't put one in but thought I would ask the experts in case I was off base. Answers on whether it needed bolts are pretty much what I thought. How to do it answers were enlightening. Will ask others with a free standing, movable table. Any issues with it moving around underway or instability when confronted with the effect of a complete idiot in a sportfish?!?! I guess some freestanding table are more appropriate than others....

firstbase said:

Second, what fastening is needed for the settee? Through bolt again or just screwed down to deck? I would think that the weight and shape would keep it pretty grounded with minimal fastenings or is that foolish thinking?
.

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Not foolish at all! A lot of much larger vessels just screw the furniture down without backing plates. On my own boat (42' Ocean Alexander) the manufacturer simply has the coffee table in the salon sitting on carpet, no fastening. It's a high low table so if the weather is getting a little "snotty", we just lower the table to its lowest point and remove anything that's on it. Just finished my 4th year with this boat & everything is fine! BTW, I don't take the boat out in weather that might toss the table around in the salon!

FB
Vertical shouldnt be a problem in your case if you choose the right L seat mount it to the seat base.
1-2 removable access plates hidden under the seat could provide access if you cant easily remove headliner.
Two birds w one stone as they say. Removable moveable storable useable elsewhere provides a lot of flexibility.
I've already thought of 2 places it might work for me on boat & motorhome... ah the project list keeps growing.

The original GB set you show was not bolted through. If I recall there were 8 #12 screws holding down the table. The table is only 20 or so inches high so leverage on the base is relatively small compared to the base diameter. Bolting through I believe would require the headliner removal.

Maerin said:

An additional thought- if you're making holes in the deck and it's cored, you should pot the holes with thickened epoxy. Drill the hole in the deck and through the coring but don't penetrate the inside laminate. Cut the coring back with an allen wrench in a drill, vac out the debris, wet it out with plain unthickened epoxy then fill the cavity with thickened epoxy. When it cures, you can drill the hole for the fastener. The epoxy plug seals the coring so no water can enter the core when the bedding gives up. The plug also provides structural integrity to keep the through bolts from compressing and weakening the core. Any penetration through a cored structure should be done similarly. Yes, it's a PITA, but it's the proper way to penetrate that structure.

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I agree with this, all except the allen wrench technique. Has anyone actually tried using an Allen wrench chucked into a drlll to try and hollow out the core? It might work OK if the core is rotten or maybe foam, but it doesn't work well at all with a plywood or balsa core that's in good shape. I tried it, and it just didn't work.

The best thing I found was using a Dremel. They have a toothed round cutter that will fit inside a 3/8" hole. Since the shaft is only 1/8", you can insert the cutter into the hole and route out 1/8" of the coring all the way around the perimeter. Then fill the hole with epoxy. When it's cured, re-drill the hole for your fastener. Now the hole has a solid epoxy sleeve all the way around it, and the sleeve is held in place by the top skin of the deck. If your fasteners are 1/4", the sleeve is 1/4" of epoxy on all sides.

i have used an allen wrench on lots of different cores including plywood with good success. I cut the short end down to about 3/8” and that works well. I also sharpen the cutting end.

Comodave said:

i have used an allen wrench on lots of different cores including plywood with good success. I cut the short end down to about 3/8” and that works well. I also sharpen the cutting end.

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Maybe not sharpening the end was my problem! All it did for me was shake the hell out of the drill.

Oh, it still shakes but it does work for me.