Rosborough Saddle Tank Removal

Chappy Daze

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The starboard tank in my very used RF-18 is weeping gas out the bottom (empty now) so needs removal; does anyone else have a setup like this? It's held in place by permanent fiberglass "end caps" 'glassed to the inside of the hull; I don't want to employ the Sawzall if there's a cleaner means of removal-- but am sorta stumped. I may be missing something simple, and am open to all suggestions!

Tank Placement.jpg

Tank Left End.jpg

Tank Right End.jpg
 

Cool Boat

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Good pictures. I'd try to remove the easiest to get to end cap to facilitate removal. I believe a diamond tipped blade (5-10$) from Harbor Freight or such on a die grinder (or hand grinder) would be a lot cleaner than sawing with a toothed blade. Check it out thoroughly before cutting as the hoses and access may be an issue too. You may be able to just cut a part of the flange off rather than cutting it back at the hull joint. After you get the tank out you may want to take a good look at the leak failure point. If it was where the tank rested on the fiberglass you may want to redesign the installation some. We had a Wellcraft years ago that developed a gas tank leak where the aluminum touched the fiberglass, and likely held moisture. A piece of rubber in the joint may help this. Be careful that the remaining tank gas fumes are not around open flames too. Maybe post some follow up pictures too. Good luck with it.
 

Chappy Daze

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Thanks! I do suspect that the leak is located at the aft bottom corner. A friend has recommended a radiator shop on the Cape which might be able to salvage the tank by coating the inside with epoxy-- but that's down the line. I'm now wondering how Rosborough would have 'glassed those end caps, as I call them, securely to the hull sides if there tank were already in place; seems like it would've been a lot easier to add the end caps first, then insert the tank somehow. I haven't detected any room to slide the tank forward or aft to free up one edge; it seems to be in there really snug.... but I need to investigate a bit more. Otherwise, a diamond-tipped blade sounds like the way to go!
 

Genius

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sawzall flush with the hull, only need to remove one of the end caps it appears. It may damage the tank depending on how tight it is against the hull. The access to the top of the tank is bad. Think about how all the fittings are going to be installed upon repair.

My new favorite tool for fiberglass cutting is the Fien tools. I have a Makita battery unit. If you go slow and ensure the cuttings are being removed, the high speed steel blades last a long time. Surgical precision with straight lines. It would be perfect for this job you have.
 

Chappy Daze

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Thanks for the suggestions! My long-term vision is to build seat boxes with tanks underneath them, like this beauty here.... but that's way down the line. In the meantime the saddle tanks are helpful for balance, and moving the weight of the fuel forward vs. portable tanks aft. I'll post pictures of the removal!

Seat Boxes.jpg
 

Bern

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Ditto Genius; carbide tipped "Fein" tool style blades are available anywhere, +/- $ 15. ea. Perfect for that job, less chance of ignition.
 

dadsboat

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We have tanks like that but they are just bolted to braces, not glassed in that way. I'm on my third reciprocating tool: this time I spent $100 more and got the Fein multitool. It is a whole new level. Beautiful control and power, no vibration too. I got a set of renovating blades in an handy box for it. I agree: that would be the tool to get that tank out. Please me know how your repair goes.
 

Aboard_Adventurer

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Any cutting around a gas tank needs to be done with something that can't spark. I third or fourth the multi-tool with a bimetal or carbide blade. They are much safer and easier to use in a situation like this than either a saw all or a grinder. If if we're me, I'd fill that tank with water right up to the brim before any demolition work. Gas fumes go boom and it would be an unfortunate end to both you and the boat.
 
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