Tell me why this idea is stupid

[aborgman]

As I'm ripping out the deck in my Glastron V-147 I'm thinking of just how I want to replace it. My preference is for a removable deck. Here is my thought -

The original deck was fiberglass over 1/2" plywood. The plywood only went out to about 1" from the hull, the very edge where the deck attacked was only fiberglass ~1/8" thick. Deck was supported on stringers (light blue in drawing), and two cross supports (purple).

My thoughts for removable deck:

Cut out all plywood leaving 1" flange of fiberglass where old floor attaches to hull.

Extend two cross supports and screw/glass them to fiberglass flange at each end.

Create ledge to attach decking -

"Peanut butter" hull side of resin soaked/glassed 1"x2" and screw in place. Once "peanut butter" is hardened, remove screws and drill screw holes out oversize, fill with resin, re-drill to screw size. Glass over 1"x2" and flange.

1/2" plywood decking will be screwed down to 1"x2" with finishing washers at outside edge. 1/2" plywood decking will be screwed down to stringers/cross supports everywhere else. All holes will be drilled oversize, filled with resin, and re-drilled to screw size.

So... will it work? Dumbest idea ever? Good way to do a removable deck? Provide enough stiffness when screwed?

--
Aaron

 

[tashasdaddy]

Re: Tell me why this idea is stupid

i don't understand what you are trying to accomplish.

 

[fixb52s]

Re: Tell me why this idea is stupid

Why? Is your goal to just add a deck that you can easily replace in a few years? Would this be a way to check the foam every now and then?

It seems like a lot of work. IMHO, I would just replace it the correct way, and not worry about it for a number of years. If your fuel tank is in the middle of the hull, I would advise something like this (ie: a removable panel) so you can gain access to it without ripping out the entire deck.​

 

[aborgman]

Re: Tell me why this idea is stupid

Why? Is your goal to just add a deck that you can easily replace in a few years? Would this be a way to check the foam every now and then?​

Basically my plan is to make the deck and foam removable, and pull up the deck and foam every fall when it gets put in storage for the winter.

It seems like a lot of work.

It really doesn't seem like all that much more work to me - I have to cut/fit the same panels for the actual deck, and instead of having to glass both sides of the deck panels, I will have to glass the attachment flange.

--
Aaron​

 

[CATransplant]

Re: Tell me why this idea is stupid

I see what you're getting at, but I can see a problem. Screws don't hold well in resin. It's too brittle, and they'll surely come loose as the boat flexes and moves.

I definitely agree that Glastron's design wasn't a good one, there, but they never thought anyone would have the boat long enough to replace the floor. They built it to be easy to assemble at the factory, and that's it.

 

[aborgman]

Re: Tell me why this idea is stupid

i don't understand what you are trying to accomplish.

A removable deck, not fiber-glassed into the hull.

Basically my plan is to make the deck and foam removable - then take them out each fall to make sure it isn't retaining any water, doesn't have any rot starting, and there is no saturated foam.

--
Aaron

 

[TriadSteeler]

Re: Tell me why this idea is stupid

One thing that may be an issue is the flexing of the hull. With the entire deck being filleted into the hull, you have the forces on the hull being distributed along the entire deck/hull joint which distributes a major portion of that force along the entire deck and hull. When you attach the deck to the flanges you will be creating concentrated areas where the forces are going to accumulate. There is going to be considerable stress placed on the screws that are holding the deck down to the flange. Rather than spreading that force across the entire deck/hull joint, it will be in hot spots where the individual screws are and in the 3" area of the flange.

I could be totally off base, but I'm thinking this could create the conditions situation similar to what happened to baineyg's Tahoe in another thread.

I like your idea from a practical point of view, but I would run it by a naval architect before I'd risk ripping my hull to shreds or at least twisting it out of shape.

 

[oops!]

Re: Tell me why this idea is stupid

A removable deck, not fiber-glassed into the hull.

Basically my plan is to make the deck and foam removable - then take them out each fall to make sure it isn't retaining any water, doesn't have any rot starting, and there is no saturated foam.

--
Aaron

aaron, your thinking is good. but there is a few problems with that approach.

the deck of the boat is structural......very structural....it needs to be fiberglassed in on most boats. thats why when you ripped up you old floor "it seemed" like it was just 1/8 inch glass holding it there.

might i suggest a different approach that will give you what you want and also give the boat what it needs?

build the whole deck as strong as you can.....glassing the bottom, and sides as well. add inspection holes thru the deck in inconspicous areas. (about 10 ins big)
add your removable foam thru the inspection holes. im going to use old life jackets for floation. each one holds 200 lbs....if your boat is 1500 lbs u need 8.....4 in each side!

that way you can remove the floatation at the end of every season...keep the underside dry and have visual inspection of below decks.

this very idea was the premise to the "boat rot wet foam prevention thread"
one of the most in depth discussions on foam recently

just some food for thought

cheers
oops

 

[AMD Rules]

Re: Tell me why this idea is stupid

I agree.... the boat's strength and stiffness relies on all components in unison, and they behave as one entity. Hull, stringers, transom, floor, sometimes foam, gunwhales, and the deck. Changing any major part of that ensemble, could (might) jeopardize the boat's integrity.

Not to say that it can't be done, but its wise to consider the 'what ifs' before jumping into it.

I've seen lots of aluminum boats with removeable floors, but they typically have aluminum stringers, and bulkheads that render the floor a cosmetic-only item, or at least subject to low levels of stress at the fasteners.

 

[aborgman]

Re: Tell me why this idea is stupid

One thing that may be an issue is the flexing of the hull. With the entire deck being filleted into the hull, you have the forces on the hull being distributed along the entire deck/hull joint which distributes a major portion of that force along the entire deck and hull. When you attach the deck to the flanges you will be creating concentrated areas where the forces are going to accumulate. There is going to be considerable stress placed on the screws that are holding the deck down to the flange. Rather than spreading that force across the entire deck/hull joint, it will be in hot spots where the individual screws are and in the 3" area of the flange.

The deck would be screwed to the 1"x2" - and the 1"x2" would be screwed and glassed to the flange left from the original deck.

The 1"x2" to the original fiberglass shouldn't be an issue - because it will be glassed in - so that leaves where the decking attaches to the 1"x2"... and I would think with a screw every 4-6" it would tie it together pretty well.

--
Aaron

 

[aborgman]

Re: Tell me why this idea is stupid

aaron, your thinking is good. but there is a few problems with that approach.

the deck of the boat is structural......very structural....it needs to be fiberglassed in on most boats. thats why when you ripped up you old floor "it seemed" like it was just 1/8 inch glass holding it there.

It didn't seem like there was 1/8" of glass holding it in, there WAS an 1/8" of glass holding it in.

The 1/2" plywood only went to about an 1" from the hull all the way around - that last inch out to the hull was 1/8" fiberglass with no wood under it.

build the whole deck as strong as you can.....glassing the bottom, and sides as well. add inspection holes thru the deck in inconspicous areas. (about 10 ins big)
add your removable foam thru the inspection holes. im going to use old life jackets for floation. each one holds 200 lbs....if your boat is 1500 lbs u need 8.....4 in each side!

that way you can remove the floatation at the end of every season...keep the underside dry and have visual inspection of below decks.

It's a nice thought - the only problem is that there really is no "inconspicuous" place to put an access on this boat... and due to how small the deck-hull gap is you'd probably have to have several access holes to be able to get the flotation in...

--
Aaron

 

[aborgman]

Re: Tell me why this idea is stupid

I agree.... the boat's strength and stiffness relies on all components in unison, and they behave as one entity. Hull, stringers, transom, floor, sometimes foam, gunwhales, and the deck. Changing any major part of that ensemble, could (might) jeopardize the boat's integrity.

Not to say that it can't be done, but its wise to consider the 'what ifs' before jumping into it.

Yeah, that is why I'm asking... Considering the way the original was put together it's hard to believe I could end up with something weaker, but I don't want to be swimming either.

--
Aaron

 

[redfury]

Re: Tell me why this idea is stupid

You could put an inspection hole right in the middle of the boat and stuff all your life jackets in the area right along the keel ( middle ). There are nice screw in plates that would work well that sit flush and can be stood upon.

I think that in the end, if you did this, you'd probably end up not pulling the deck off after a couple of times. For one, it would be a major PITA to do. Secondly, the screws would get to the point where they wouldn't hold after a few times unless you found the right "torque" to keep them in without coming loose, and not being so tight that they ruin the hole they are in, or sink into the deck.

Boats are like unibody cars, and they weld the frame to the unibody cars, not screw it on. I think your concept is solid though. I just think the bigger problem is just the sheer number of screws you'd need to pull to get the deck off every year. If you build the deck right and get the right flotation in there, you shouldn't have to worry about it. I think the majority of problems with boats are the ones that are parked outside, have to deal with the temperature changes of winter climates or extreme heat of summer causing expansion and contraction.

 

[aborgman]

Re: Tell me why this idea is stupid

You could put an inspection hole right in the middle of the boat and stuff all your life jackets in the area right along the keel ( middle ). There are nice screw in plates that would work well that sit flush and can be stood upon.

I like the idea, but there is so little space below the deck that just about every space between stringers need to be filled full with foam. The biggest accessible "compartment" would still be pretty small.

I think that in the end, if you did this, you'd probably end up not pulling the deck off after a couple of times. For one, it would be a major PITA to do. Secondly, the screws would get to the point where they wouldn't hold after a few times unless you found the right "torque" to keep them in without coming loose, and not being so tight that they ruin the hole they are in, or sink into the deck.

Yeah - I can see it being a pain with the large number of screws, although the loose hole can always be fixed by re-filling and re-drilling the hole.

If you build the deck right and get the right flotation in there, you shouldn't have to worry about it. I think the majority of problems with boats are the ones that are parked outside, have to deal with the temperature changes of winter climates or extreme heat of summer causing expansion and contraction.

This boat will be parked outside, year round, in Southeast Michigan.

Our coldest day last winter was almost -10F.

We hit 92F yesterday.

--
Aaron

 

[CATransplant]

Re: Tell me why this idea is stupid

If I remember correctly, too, the console and the livewell/cooler/seat dealy is integral with the deck, and adds a great deal of strength to the whole assembly. Again, it has been a while and I never had mine apart. I really think, in the long run, you'll be better off duplicating the original setup. I mean, it lasted almost 40 years that way, so they at least had something right going on, despite the flimsy look of the thing.

The transom could be improved, as we discussed in the other thread, but I'm not all that sure I'd mess with the inner hull design.

 

[aborgman]

Re: Tell me why this idea is stupid

If I remember correctly, too, the console and the livewell/cooler/seat dealy is integral with the deck, and adds a great deal of strength to the whole assembly. Again, it has been a while and I never had mine apart. I really think, in the long run, you'll be better off duplicating the original setup. I mean, it lasted almost 40 years that way, so they at least had something right going on, despite the flimsy look of the thing.

True - and the original floor was in surprisingly solid condition (especially considering the bottom side was un-glassed, un-painted, bare plywood) - don't know about the stringers yet, but the foam seems pretty unsaturated.

I just don't want to fix it, then be having to rip it all out again in a few years... and I definitely worry abut the drainage.

The transom could be improved, as we discussed in the other thread, but I'm not all that sure I'd mess with the inner hull design.

Anyone see any problem with using the fiberglass "flange" from the original floor to glass the new floor into?

--
Aaron

 

[tashasdaddy]

Re: Tell me why this idea is stupid

personally, i see it as a complete waste of time and money. if you keep your bow high, and the boat covered when not in use. it will last longer than you want to keep it. most boats that need decks, have not been properly care for.

 

[j_martin]

Re: Tell me why this idea is stupid

If you take the effort you're considering putting into the removeable deck, and put it into high quality construction, you'll not have to mess with it in your lifetime.

CPES (clear penetrating epoxy sealer) treated wood parts is probably the key to longevity. Find someone to put in closed cell foam in the voids, or blind glass the floor in such a way as to have seperate air pockets such that if one gets punctured, the others around it don't get flooded.

hope it helps
John

 

[Mark42]

Re: Tell me why this idea is stupid

You want a removable floor to inspect foam and remove it so you don't have rot issues. Its a means to an end, but there may be better.

In light of the Coast Guard regulations for boat foam,

Flotation material located at the sides, as far aft and as high as possible, will help make boats with machinery located aft float level when swamped. Some boats may require the keel area inside the boat to be void of flotation material so that the space can flood from either end to provide proper balance in the swamped condition.

how about following their advice and do this:

1) put in new floor and stringers and leave the foam out of the floor. No foam, nothing to hold water and cause rot. And you no longer need need a removable floor, just some inspection hatches. Can double as storage compartments under the floor.

2) put the foam where the CG suggests, in the gunnels and transom. This has the advantage that the foam does not sit in water where it could possably absorb some. It also puts the flotation above the floor so if the boat got swamped, the foam is high, and keeps the boat from flipping over.

A method of foaming the gunnels is to pour un-expaned foam into large trash bags with no air. Then place the bag against the gunnel, or under splashwell with a piece of plywood forming the cavity while the foam expands in the bag and takes the shape of the cavity. Its in a bag, so it won't stick, and you can carve it, remove and reinstall until you are ready to glue in place using more foam or contact adhesive or the like.

You may want to browse this USCG puplication on boat building:

http://www.uscgboating.org/safety/boatbuilder/index.htm

 

[wil7483]

Re: Tell me why this idea is stupid

personally, i see it as a complete waste of time and money. if you keep your bow high, and the boat covered when not in use. it will last longer than you want to keep it. most boats that need decks, have not been properly care for.

Ditto!!!! The floor to hull joint is a structural element that does not need to be Billy Bob'd back together. Under stress your boat will flex, the joint will fail, and you will be swimming, if you're lucky. But if you are bent on this foolishness then by all means go ahead.