Merc 340 airdeck advice

[rmoore8118]

The keel stiffener which runs port to starboard at the front of my boat, between the inflatable keel and the underside of the airdeck has cracked. It appears there was a knot at the point of cracking.

Question is, should I replace with the same thickness of plywood, thicker, or some other material?

 

[TOHATSU GURU]

Re: Merc 340 airdeck advice

Not critical.

 

[Ocean Man]

Re: Merc 340 airdeck advice

The keel stiffener which runs port to starboard at the front of my boat, between the inflatable keel and the underside of the airdeck has cracked. It appears there was a knot at the point of cracking.

Question is, should I replace with the same thickness of plywood, thicker, or some other material?

Hey cant help but how do you like the boat im looking at the 310 Air Deck with a 9.9hp. How does yours perform any bay or ocean ?>

 

[rmoore8118]

Re: Merc 340 airdeck advice

I like it fine. Use it as a toy with my RV lifestyle. Rolls up nice and compact. I run a 9.5hp and it's FUN with one person (18 - 20 mph per GPS), will get on plane with 2 up. I've never had it in the ocean, but it is was very stable and a lot of fun in 3'ers on Lake Michigan this summer. Even with 4 aboard it was very stable, although VERY slow. I really want a 15 hp.

 

[Sea Rider]

Re: Merc 340 airdeck advice

An air deck is more portable and much faster to assemble compared to same wooden or alum panel floor sibs, you'll need to inflate air floor to it's recommended pressure as it tends to rock if it's not inflated properly. You could update that engine latter if transom tech plate accepts larger engines. If sib is heavily loaded, don't expect much performance out of that engine.

Happy Boating

 

[rmoore8118]

Re: Merc 340 airdeck advice

IIRC the 310 takes up to a 10hp and my 340 is certified for 15 HP.

 

[Sea Rider]

Re: Merc 340 airdeck advice

Question is, should I replace with the same thickness of plywood, thicker, or some other material?

Better replace with same playwood thickness, thicker with time will abrade or unglue floor fabric sides where stiffener sits, specially when air floor is infalted to it's max recommended working pressure, floor fabric was asssembled for that playwood thickness. Paint with a good paint that will seal playwood pores against water intrussion.

Happy Boating

 

[rmoore8118]

Re: Merc 340 airdeck advice

Better replace with same playwood thickness, thicker with time will abrade or unglue floor fabric sides where stiffener sits, specially when air floor is infalted to it's max recommended working pressure, floor fabric was asssembled for that playwood thickness. Paint with a good paint that will seal playwood pores against water intrussion.

Happy Boating

Thanks, that's the advice I was looking for.

 

[CapeAnn]

Re: Merc 340 airdeck advice

Thanks, that's the advice I was looking for.

I have the same Airdeck too. I do notice that the stiffener gets a lot of strain and interesting to note that it is made wood. Thanks for bringing this up as I will have to look carefully at the device next time I deflate everything. If mine goes South I might replace with something less prone to cracking - Trex, or composite materials??? Also using a 15 hp as I've noticed that with bigger inflatables and with +2 passengers not enough umph.

Cheers,

CapeAnn

 

[Ocean Man]

Re: Merc 340 airdeck advice

Would some Marine Ply wood on top of the inflatable floor help? I plan on making the 9.9 hp into 15hp and most people i will have on will be 4 but most of the time it would be 2. or 1. I plan on fishing with this so i hope i have the right idea.

 

[rmoore8118]

Re: Merc 340 airdeck advice

I don't think plywood on top is necessary nor advisable. This piece under the floor does see a lot of strain and tends to take on an upward warp over time. I usually flip mine over annually. My crack was right down the center of the support, and I can see that there happened to be a knot on the top ply of the wood there. I'm sure that weakened it. Also the crack appeared after having a lot of FUN running WOT in 3 footers and jumping the waves. I'll look into alternative materials, but hey, if you have to replace the stiffener every few years.....no biggie. It'll only take about 30 minutes to make one, maybe another 30 minutes to paint a couple of coats.

 

[Sea Rider]

Re: Merc 340 airdeck advice

Would some Marine Ply wood on top of the inflatable floor help? I plan on making the 9.9 hp into 15hp and most people i will have on will be 4 but most of the time it would be 2. or 1. I plan on fishing with this so i hope i have the right idea.

You could place a thick carpet ontop air mat well trimmed to match top air deck contour, get one that's not slippy and that does not holds water inside as this will add more weight to sib. When placing a new wooden keel stiffener, round with sand paper all contour, specially lateral corners that rests against floor/tube fabric to avoid abrassion.

Happy Boating

 

[rmoore8118]

Re: Merc 340 airdeck advice

For sure match the original rounding and smoothing on all edges. Sea Rider, re. your previous post....since the weak point on these is the center where the inflatable keel pushes up, what if I took a thicker plywood and then mitered down the ends to match the original thickness where it rests under the tube to floor seam. Of course matching the smoothing and rounding off of edges?

 

[Sea Rider]

Re: Merc 340 airdeck advice

It all depends on how much pressure you want to have the keel inflated to, if you want near boating/cruising perfection with an air mat sib, will need to have tubes, air mat and keel inflated to it's max factory recommended working pressure. Keep in mind that in the long run, adding a thicker playwood at middle keel will abrade more keel fabric, will push stressing keel deeper that doing so with stardard one. Air floors usually have 2 handles under bow side to fit baord so as not to move sideways while boating. You could try a thicker one and see what happens, or make 2 same original pieces and keep them as spare parts.

Happy Boating

 

[Ocean Man]

Re: Merc 340 airdeck advice

Is there a big difference in the 310 and 340 as per interior size?

Do you think 2 adults around 240lbs with cooler + fishing gear in a 310 with 9.9 would work for bay fishing ?

Thanks


Also would a 03 merc 310 with 03 9.9 merc air floor for 1200 be a good price or a price you would pay if you were looking ?

T

 

[Sea Rider]

Re: Merc 340 airdeck advice

Besides 30 more cm in lenght, probably 340 is bit wider, check tech specs to see. Used to have may moons back a 310 sib with a 9.9 engine, cool for 2 + gear, personally would go for the 340 + 9.9 HP future updatable to a 15 HP while maintaining same sib size.

You are reffering to a 2003 merc 310 air floor sib with merc 2003 engine, right. what's the sib state overall condition ? Can you place pics of that combo to have a look ?

Happy Boating

 

[TOHATSU GURU]

Re: Merc 340 airdeck advice

Yes

Yes

That's a steal if the boat is Hypalon. About right if it's PVC. If it's PVC it is at the end of it's service life.

 

[Ocean Man]

Re: Merc 340 airdeck advice

No pictures on the setup but they say its really clean with low hours and would like me to come see it.. Only problem i have is this boat is already with its second owner and i know nothing about outboard motors or what to look for in a boat. I also have an offer out on a 12' saturn with a 9.9 hp 4 stroke.

What does end of service mean ? am i better off just buying a new inflatable and a used motor? Motors are cheap out here.

 

[TOHATSU GURU]

Re: Merc 340 airdeck advice

PVC fabric boats tend to fall apart after a few years. After six to 10 years they usually have reached a point where so much is wrong, that they visit the dumpster.

 

[Sea Rider]

Re: Merc 340 airdeck advice

Probably seams, floor fabric, accesories will tend to unglue rather than fabric falls apart, you cannot place all mature pvc sibs in same sack, the condition will depend on where the sib was kept, shaded, unshaded, rolled, unrolled, heavyly used and above all abused, etc. My Quicksilver Korean made 340 wooden floor bought in 1998 is on it's third owner and in impecable conditions, because it was and is well cared for. For your peace of mind and wallet go for a new one if possible.

Happy Boating