removing rib between stringer

kevinmi

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I am removing a gas tank on a 204 overnighter. Directly behind the tank is a rib that runs between the longitudinal stringers. Is this in fact a stuctural rib or is it only for locking in the gas tank?

Also in removing the tank it appears I will need to cut the lip around the parameter of the deck hatch. I am thinking of using some type of rotary cutter, any recomendations?

Finally, since it would be difficult to replace the cut the lip around the parameter of the deck hatch, without grinding on the finished deck. I was planning on using 5200 to adhere a new deck lip. The weight of the deck hatch is supported by rib/cross members, with the lip providing a sealing point for the silicone.

Let me know.
 
kevinmi said:
Directly behind the tank is a rib that runs between the longitudinal stringers. Is this in fact a stuctural rib or is it only for locking in the gas tank

Normally, that would be a bulkhead...it should be replaced.....why do you need to remove it?

The perimeter is normally a thin layer of glass....can be cut with a small rotary saw , they work well from people I know who have used it.....a sawz-all is crude but will work...but for fine tuning, I like using the Fein tool...pricey, but perfect for situations like this...you'll have total control of the blade...I paid 300 for a large kit, but I think its worth it..

To re-attach, use epoxy, not 5200...too thin for a backing to hold well....I still don't understand why this needs to be cut....can you post a picture?
 
I am going to attempt to remove a friend's this morning. I don't think you will need to remove any bulkheads or cut any fiberglass - at least I hope. I have read, on here, that although tight, it is doable...
 
Thanks for the replies,

I am removing the gas tank(leak) on my 1988 204 overnighter. The tank is 64"long x 11"deep x 23"wide the hatch cover opening above the tank is appr. 63" long x 22"wide so I need to remove the lip the hatch cover sits on so the tank can be removed. Additionally, the tank needs to be slid back from its current position so that it is directly below the hatch opening. But there is a bulkhead at the sternend of the gas tank preventing me from sliding the tank below the hatch opening.

So my plan is to cut the bulkhead (whick looks like a glassed in 2foot - 2x12 between the stringers) ,cut the lip which goes around the perimeter of the hatch cover, giving me the additional inch or so I need to fit the tank out. Then replace the bulkhead and finally attach a lip with 5200. The reason I thought of using 5200 and not fiberglass was I didn't want to grind any of the deck that is visible. The weight of hatch is supported by a bulkhead and other members. The lip is mainly for a seal.

Why did GW make the opening an inch to small in both directions? I did call GW and was told the tank would fit out but I would need to cut the lip.

Let me know what you think......thanks

Great to get feedback.
 
Thats messed up...sounds like they installed the tank before putting the deck on....my sailfish has room all the way around...no lip cutting required.

Since you are cutting the bulkhead out you will need to do some grinding and glasswork...the lip is basically an "L" shape at the base of the deck....if you cut it off, you only have 1/8 inch of material to glue to...not much..don't know how you would even do it.....If it were me, I would epoxy a thin 1/4-3/8 wood strip in the area under the lip and under the deck against the stringer around the entire box...that would be your support for the lip edge....you should have enough space to do this after the tank is in...hopefully...but you'll need to do the prep work when the tank is out. Do you have any pics? Maybe you can get away with only cutting one side and the rear lip?
 
Kev...looking at that picture, I think I could get that tank out without cutting the deck lip....it is shoved forward so lifting the aft end may be a bit*h but worst case scenario is you pull the rear bulkhead and that should do it......I would try it step by step....all the hold downs and wedge blocks removed first....if it can't clear the rear bulkhead, remove that.....then the last course of action would be cutting the glass lip on one side only....I can see some daylight on both sides of the tank based on that picture....a little swearing and sweat should get it out.....get some straps/rope and a friend and go for it...

heck, that rear bulkhead doesn't even looked glassed in as a structural part....it doesn't touch the stringers! I see space and the pink sender wire on both sides of the bulkhead....that should be easy...
 
Richie,

Good ideas, I will take it step by step, if needed remove bulkhead, if needed remove lip. Replacing the lip shouldn't be a big deal. I just wanted to do a sanity check before I started cutting. Thanks for thinking it through, much appreciated!

GW put me in contact with RDS they have the exact replacement tank.

Kevin
 
Tank should come out by cutting back the deck on the stern side by an inch or so. I would really hesitate to go chopping into that bulkhead.

Have done a tank swap on my 85. You should not have to compromise the hull integrity to swap a tank.

Search my posts for this project, if you do not find what you want let me know.
 
Kev, not sure if the GW website pic says anything about your particular situation, but the previous pic of the overnighter is pretty clear...that piece of wood is not a true structural member....its not glassed to the sides/stringers, and its not even glassed on the ply itself...it looks to be simply bedded in resin putty and probably tabbed in with some 4 or 6 inch tape on the bottom....thats much easier to remove and replace than cutting the deck and trying to make it look good again....actually, when you replace the ply and re-bed with epoxy putty, you can make it part of the structure by glassing all the way up and around....it will be better than the factory....just need to grind the surrounding glass by about 4 or 5 inches on each side to rough it up and add 2 layers of 12oz biax tabbing and 2 layers of 17oz biax glass...it will be a true bulkhead at that point....

But try to pull is first without cutting anything if you can...it may be a PITA, but may save you some work down the road.
 
Agree with rr. That pic shows it's certainly diferent than my 85 wich has a full coffin for the tank.

Curious, what's behind that plywood, open bilge?

Is that a full 65 gal. tank, doesn't seem as long as mine?