floor on FC470

[boostingmorale]

I have a 2007 4.7 mkgr3 (15 INCH TRANSOM)

My floor wont lay flat... get a big banage bend the bow digs into water when i try accelerate

is there different floor options?

can i just weld them all together to make it flat when i deflate the boat

(yes im deflating, making floor flate then trying to re in flate

pictures;

20151209_1100261.jpg Photo by Peter_Wells | Photobucket

20151209_1108071.jpg Photo by Peter_Wells | Photobucket

20151209_1107551.jpg Photo by Peter_Wells | Photobucket

20151209_1107491.jpg Photo by Peter_Wells | Photobucket

any ideas how to fix it?.. havent even used this piece of shit properly yet

[cgoing]

Well I am 99.9999999 % sure that boat us not a 2007 . Unfortunately I believe it is more like a 1987 maybe older. The Grand raids have not had thrust boards for many years. I have a 1997 and the Thrustboard were gone long before then. Also that does not appear to be the correct floor for that boat.

[boostingmorale]

im guessing yours is a 20 inch transom?

mine is 15inch and is ex (australian) army

the plate states it is indeed a 2007 build.

[boostingmorale]

and in fact can you not bother replying unless its constructive,

thanks in advance

[cgoing]

I was not trying to be negative . Unfortunately I see many customers who buy used inflatables that are ex surplus from Military and they end up with mismatched floors that do not fit correctly. My best friend bought a Zodiac F 470 that he was led to believe was a good deal only to find out when it arrived here the floor was not correct for the boat and has the same issue as yours.

Good luck solving your issue.

[Attack Ducks]

It is possible to knock the side pieces off a floor section then slide (pound) off one of the inner "segments" then put the floor section back together (you will probably need to cut down and smooth out the side pieces as well. Do some careful measuring to see which segment to remove (they vary in width).

I have done this before. Whatever you do, do not try to force a floor in that is too long, expecting the boat to "stretch." I've seen a couple boats damaged this way it caused a main seam where a number of joints overlap near the bow thrustboard to begin pulling apart and is a major PITA to fix!

[boostingmorale]

hoping I can weld floor board 1& 2 together to make it rigid

[boostingmorale]

http://www.rib.net/forum/f50/zodiac-...ons-32776.html


looks the same as this??

[jyasaki]

Aren't your stringers in the wrong place?

I don't know about the FC470 floors, but aren't those wooden guys at the outside edge of the floor supposed to brace the sections and keep them in-line?

jky

[dave3235]

+1 stringers should not join on a join what size are your stringers do you have two plus two ie 2 one size and the other 2 are another size,then you stagger them.

[kelson]

First off, relax. A lot of us had issues with our used boat purchases and everyone would like to see you have a great time with your boat.

Just because the boat is unusual doesn't mean it isn't a 2007. Some are built to spec. But the name plate might not be original either. I've seen that dodge to get a plate on a surplus before. We see a lot of surplus FC470s here in San Diego because the Navy Seals burn through them. A lot are sold as scrap with plates removed and no floor. I haven't seen a FC470 with that bow dodger/spray shield fabric on the front in decades. But anything is possible.

I own a 98 Zodiac Futura. It has an aluminum floor. The black plastic stop block that is seen at the joint in the photo, that is at the end of the last aluminum floor section at the rear of my boat. All aluminum floor section joints are covered by the aluminum rail sections that fit into place. There are NO wood sections of rail. Whatever wood rail sections you have are not original issue. You might look at your order of installation and see how it fits with that section at the back. The very front joint, where my aluminum floor transitions into a last wood floor section, does not have a rail section holding it into place. The boat flexes right at the bow and the floor section there is held in by the tubes when inflated. There is no rail section on the front wooden floor section at all.

When I install my aluminum floor I have the boat mostly deflated. I have to stand on the "tent" or raised joint to get the floor to lock in place. Best done when warm.

As far as welding the hollow aluminum floor sections together, that won't provide much strength. The rails are very important. See if switching your floor section order can enable you to use the rails as intended. Having them go all of the way aft is a waste of the rail. Wood rails, while clearly not OEM, do work fine and they are on many older Zodiacs in use.
Good luck with your Zodiac!

Don't know what you paid, not sure of what you actually have for a floor, but a nice hypalon zodiac will last a long time with a little care. Sure wish my Futura was hypalon!

[kelson]

Took a look at my buddies zodiac and it does have a stop block at the front of the front aluminum floor section. But not at an intersection of two aluminum floor sections. Hope you just have your order wrong.

[boostingmorale]

Originally Posted by jyasaki

Aren't your stringers in the wrong place?

I don't know about the FC470 floors, but aren't those wooden guys at the outside edge of the floor supposed to brace the sections and keep them in-line?

jky

well that's what they are doing for the last 3 panels...

[boostingmorale]

Originally Posted by kelson

First off, relax. A lot of us had issues with our used boat purchases and everyone would like to see you have a great time with your boat.

Just because the boat is unusual doesn't mean it isn't a 2007. Some are built to spec. But the name plate might not be original either. I've seen that dodge to get a plate on a surplus before. We see a lot of surplus FC470s here in San Diego because the Navy Seals burn through them. A lot are sold as scrap with plates removed and no floor. I haven't seen a FC470 with that bow dodger/spray shield fabric on the front in decades. But anything is possible.

I own a 98 Zodiac Futura. It has an aluminum floor. The black plastic stop block that is seen at the joint in the photo, that is at the end of the last aluminum floor section at the rear of my boat. All aluminum floor section joints are covered by the aluminum rail sections that fit into place. There are NO wood sections of rail. Whatever wood rail sections you have are not original issue. You might look at your order of installation and see how it fits with that section at the back. The very front joint, where my aluminum floor transitions into a last wood floor section, does not have a rail section holding it into place. The boat flexes right at the bow and the floor section there is held in by the tubes when inflated. There is no rail section on the front wooden floor section at all.

When I install my aluminum floor I have the boat mostly deflated. I have to stand on the "tent" or raised joint to get the floor to lock in place. Best done when warm.

As far as welding the hollow aluminum floor sections together, that won't provide much strength. The rails are very important. See if switching your floor section order can enable you to use the rails as intended. Having them go all of the way aft is a waste of the rail. Wood rails, while clearly not OEM, do work fine and they are on many older Zodiacs in use.
Good luck with your Zodiac!

Don't know what you paid, not sure of what you actually have for a floor, but a nice hypalon zodiac will last a long time with a little care. Sure wish my Futura was hypalon!

paid us$ about 600 no leaks nothing.

the guy who sold it to me set it up like that. the front 'number 1' has black plastic strips the same shape as the wooden rails. there is original markings on them that show a shaded colour and to which section of floor. I will have to get some pics

[boostingmorale]

the floor is alloy?

pictures on the first page...

[kelson]

Can't see the very first floor section in your photos. I do have a small wood section at the very front, but my boat is a futura. The floor sections pictured sure look like the normal aluminum construction. Looks like all of the zodiac floors I've seen. Here are a couple of photos from when I had the side caps off to mount a cross plate. Notice how the floor is made up of connected hollow sections. Rails are very strong and rigid. I doubt a welded floor section will work. But what do I know! Previous owner had a bait tank bolted to thin floor top sheet and it cracked. I didn't want that to happen. This section has a base for a ski pole. I have another for my custom welded gas tank. You might be able to weld the large floor sections together in some fashion, but I have to have a fold in one joint to assemble the floor in place.

[office888]

Inflate the boat to 240 mb
Measure between the transom and thrust board edge
Measure the floor from end to end

The floor should be about 15mm longer than the boat measurement. If it exceeds 25mm, the floor grip exceeds factory specifications.

Ps : boat does not look like 2007 spec. The HIN plate should read something like FR-XDC... Last two digits are the year.

If you are referring to a plate on the inside that says "model / type / series : 2007" that is a manufacturer code to designate which model and revision the boat is.

[jyasaki]

Originally Posted by boostingmorale

well that's what they are doing for the last 3 panels...

The stringers (or rails, depending on the post you're looking at) should brace all of the aluminum panels, creating a flat, rigid floor. The intersections between the panels are supported by the stringers. If there are more than one per side, they should be placed such that the stringer ends meet mid-floor-panel.

The (usually 2) front pieces, thrust boards, are generally not braced, and allow the bow a little give when you stuff into a wave or whatever.

jky

[Projectile]

That's a 1980s MKIII Grand Raid.

[Projectile]

boostingmorale,

Your boat looks almost *exactly* like the 1980 MkIIIGR we used to have. We bought it new in 1980 and still have it, though it is going to be salvaged for parts and disposed of next year. It least air like a sieve. It's a boat that I'm very familiar with. I scanned and attached the original owner's manual depicting the floorboard assembly.

The 1980 model had aluminum stringers, while yours are wood (that's the only difference between your boat and ours). That suggests that it is an older model, or the stringers are not original. Before 1980, the black bakelite edges on the floorboards and stringers were wooden, and the floorboards were wooden, too, even farther back in time. Around 1980, Zodiac started offering the floorboards in aluminum, and then with a non-slip coating on the aluminum. I suspect that your model still had the wooden stringer before transitioning to aluminum stringers, so I suspect that your boat is pre-1980. In any case, the floor appears to be assembled correctly. I don't think that it's a big deal that you are missing the black bakelite edge on one of the floorboards.

The bow digging down into the water as you accelerate is almost certainly because the floorboards are failing to properly stretch out the floor fabric. If the floor fabric isn't stretched taut, the hull will be concave down when viewed from the side and that curve will be accentuated as you accelerate. This is called a "hook" in the hull, and it causes the rear of the boat to rise up and the bow to dig in. We never had that problem with our MkIII GR, but I did have it with my 2011 WB465 when the floorboards were not assembled correctly, failing to properly stretch out the hull of my boat. It is normal for the hinge between floorboards 1 & 2 to flex, but not when the boat is assembled, pumped up and resting on the ground. There would normally be flex at that hinge point when coming down over a crest and into the next one in a following sea.

There could be several reasons for your hull fabric to not be stretched taut enough.

1) The boat and keel are improperly inflated. Boats that old have leaks and it can be difficult to get the pressure up to 220/240 millibars in the keel and 240/280 millibars in the hull. A notorious spot for leaks is at the end of the buoyancy tubes where the material is glued onto the black cones that form the aft tips of the boat.

2) The thrust board is too far forward. It may have come loose and been reglued too far forward, or the material holding it in place may be partially unglued or stretched and unable to hold it in place, permitting it to twist forward. The MkIIIGR had a second thrust board ahead of the one visible in your first photo, but I can't see if it is in place in your first photo because it is too dark under the canopy. This second thrust board is not pictured in the assembly diagram from the manual because the manual used the image for the Mark II GR, which didn't have it. It's important that the wooden bow board is properly in place between these thrust boards with it's black plastic stopper up against the forward most thrust board.

3) The hull material itself may have stretched/loosened over time.

The relationship between the floorboard length and the stretched length of the hull fabric is crucial. If it's off by more than a centimetre or so, you can get a hooked hull. I know this from personal experience. The three potential causes could easily combine if each one alone is not enough to produce that kind of mismatch.

That boat is almost certainly a hypalon boat and if the material wasn't well cared for over the years, it will probably now be porous and leak air and/or have seams that leak a great deal. I'm very confident that you are dealing with a boat that is around or over 30 years old. I hope I'm wrong, but I suspect that, unless it has received a lot of TLC over those 30+ years, it's going to need some work to hold its air enough to stiffen the hull and stretch out the floor, or some work on the thrust board(s).