SoCal Jet Boats

Tech Talk => Gelcoat / Paint / Fireberglass Repair => Topic started by: crewchief22 on August 19, 2008, 06:50:46 PM

Title: Fuel tank mounting
Post by: crewchief22 on August 19, 2008, 06:50:46 PM: I'm looking for some pics of how to mount round stainless/aluminum type tanks to the hull.

My Hondo tank brackets had just one bolt at each bracket that came through the hull from the bottom side. Making the fuel fill hose the only thing keeping the tank stable (no wonder both tanks have broken at the fill spout).

Now with switching from aluminum to stainless tanks I have to relocate the brackets and want to mount them without bolting through the hull.

I'm gonna start the fiberglass repair of the existing holes soon (not what I wanted to be doing before the end of the season).
Title: Re: Fuel tank mounting
Post by: FORKEDUP on August 19, 2008, 08:40:48 PM: there was an article in hot boat quite awhile back about this, they took the tank mounts and fabbed a bracket for both both of them then glassed the bracket to the floor of the boat, i think i still have the mag. i will check and get back to you, it was a pretty slick idea and i wanted to use it, but my boat was to far into the paint stage to change it :banghead:
Title: Re: Fuel tank mounting
Post by: GT Jets on August 19, 2008, 11:45:51 PM: When I did my Renegade, we made some aluminum blocks and milled them to fit the contour of the inside of the hull and bolted them with two stailess flatheaded 5/16" bolts threaded right into the aluminum and epoxied the heads of the bolts (like you would do on the pump) then the top portion of the blocks were drilled and threaded with two hole each and I went to the Specialty Truck supply store and found some bitchen stainless steel air tank brackets for a big rig that had a really nice rubber liner inside, they just happen to fit my tanks (Stainless Moon's bought at a swap meet for $50), I don't remember how much they cost (was in 1990) but could not have been too much because I was as broke as you could get back then, (had to get a loan to pay attention) :-\

Still see that boat once or twice each year and the same tanks are still in it. Can't miss it, 19' renegade painted all black with black carpet and dark maroon seats, my ass is still smoking >:D

I'm not sure there is any really good ways to mount the tanks other than having the thru-bolted unless you have some wiggle room at the top, I didn't, the hoses were only about 3" long for the fills...
Title: Re: Fuel tank mounting
Post by: TJS Nordic on August 20, 2008, 05:02:50 AM: Quote from: FORKEDUP on August 19, 2008, 08:40:48 PM
there was an article in hot boat quite awhile back about this, they took the tank mounts and fabbed a bracket for both both of them then glassed the bracket to the floor of the boat, i think i still have the mag. i will check and get back to you, it was a pretty slick idea and i wanted to use it, but my boat was to far into the paint stage to change it :banghead:

I have that article somewhere too. I was going to post the same thing. You beat me to it.
T.J.
Title: Re: Fuel tank mounting
Post by: crewchief22 on August 28, 2008, 09:09:12 PM: Thought I would post some pics of the progress.
Title: Re: Fuel tank mounting
Post by: crewchief22 on August 28, 2008, 09:10:40 PM: A few more ;D
Title: Re: Fuel tank mounting
Post by: crewchief22 on August 28, 2008, 09:12:00 PM: More ::)
Title: Re: Fuel tank mounting
Post by: crewchief22 on August 28, 2008, 09:15:26 PM: Now this weekend I get to finish making things flat then start mounting the new tanks.

Still have not come up with a better way to mount the new tanks than bolting right through the hull, as it was before.

Help me before I break out the drill ;D
Title: Re: Fuel tank mounting
Post by: 76 Bonneville on August 30, 2008, 02:40:27 PM: Here were the brackets I made up to mount the tanks in the Rogers. The Rogers has a dropped chine that part of the bracket would drop into. I was going to glass the flat stock that connects the brackets to the bottom.
Title: Re: Fuel tank mounting
Post by: rogers tr on September 03, 2008, 09:56:20 PM: did your rogers have square or round tanks to start in the process of getting parts to switch to round stainless
Title: Re: Fuel tank mounting
Post by: 76 Bonneville on September 03, 2008, 10:06:22 PM: I sold Crewcheif these SS round tanks. I was going to use them but what I need are tanks with the filler neck closer to the end of the tank and offset to the side. So for now I went back to the original style tank but alluminum. Had to have one made by IMCO. When I find the right tanks I will swap to the round tanks, thats what I fabed up those brackets for. Ron
Title: Re: Fuel tank mounting
Post by: rogers tr on September 03, 2008, 10:13:40 PM: yeah im doin the same thing because right now all i wanna do is cover these sqaure ones up
Title: Re: Fuel tank mounting
Post by: wizard612 on September 04, 2008, 07:49:54 AM: Gee wiz guys we used to put holes in the boat all the time to mount what ever needed to be mounted, tanks plates, drop through fins,water outlets, Dad's fishing boat had depth sounders, toilet port, you get the idea. Don't get too hung up on putting some well placed accurate well sealed holes in your boat. My tank brackets & intake, never leaked. My drop though fin did a little but that was due to the fact we designed it to be movable and our machine shop consisted of a band saw and a drill press. It never leaked enough to bother a thing while racing. In fact an old trick was to put some tide in the bilge before launching (not too much otherwise you'll look like Lawrence Welk's band) it kept the inside nice and clean.
Title: Re: Fuel tank mounting
Post by: Brad @ SCJB on September 04, 2008, 09:39:19 AM: the tanks kyle had made for the wriedt (custom aluminum imco box tanks) have 4"x4" tabs welded on them to glass over. they are to replace the fiberglass ones that were very badly needing to be replaced.
Title: Re: Fuel tank mounting
Post by: 76 Bonneville on September 04, 2008, 09:56:21 AM: I know your right Wizard, thats the way its been done for years. It just seems to me, even though its more work, the less holes in the bottom the better.
Title: Re: Fuel tank mounting
Post by: crewchief22 on September 04, 2008, 12:53:05 PM: I did it, I drilled the bottom and mounted the brackets. The original tank brackets only had provisions for one bolt per bracket (I think that might have been why both tanks had cracked at the filler neck). The brackets I got from 76Bonneville had provisions for 2 bolts (but it looked like only 1 bold used previously). I've got them mounted with 2 bolts for each bracket to help keep things from breaking in the future.

Hope to have it out in the next couple weeks.
Title: Re: Fuel tank mounting
Post by: wizard612 on September 04, 2008, 01:52:04 PM: A word to the beginner... If you try to mount everything in by glassing in a block or bracket, prep the glass well by grinding all the flow coat, wax or mold release agents from where the glass will be laid over the hull. Make sure you have a lot of area where new glass meets old. and make sure the new glass is thick enough to take the load. There is a lot of weight in a 17+ gal. fuel tank and it will REALY wreck your day if they break loose in the middle of the lake.
Title: Re: Fuel tank mounting
Post by: Grimpala on January 10, 2023, 11:14:40 AM: Quote from: FORKEDUP on August 19, 2008, 08:40:48 PM
there was an article in hot boat quite awhile back about this, they took the tank mounts and fabbed a bracket for both both of them then glassed the bracket to the floor of the boat, i think i still have the mag. i will check and get back to you, it was a pretty slick idea and i wanted to use it, but my boat was to far into the paint stage to change it :banghead:

Does anyone happen to have this article. I've seen/read it, and I thought I had it saved on my computer somewhere, but I can't find it anymore.

Thanks.

Edit: Found the posting.

https://www.socaljetboats.com/hulls/saddle-tank-mounting/msg156748/#msg156748
Title: Re: Fuel tank mounting
Post by: JordanDangerfield on January 10, 2023, 05:52:24 PM: Here?s a set of tank mounts I did.
Title: Re: Fuel tank mounting
Post by: Grimpala on January 11, 2023, 09:35:09 AM: Quote from: JordanDangerfield on January 10, 2023, 05:52:24 PM
Here?s a set of tank mounts I did.

Any issues with the mounts fatiguing? Any cracking around them?

The way you did it is the way I want to, but the article shows a strap tying the two mounts together to add more surface area to glass to.
Title: Re: Fuel tank mounting
Post by: JordanDangerfield on January 11, 2023, 05:22:02 PM: Quote from: Grimpala on January 11, 2023, 09:35:09 AM
Any issues with the mounts fatiguing? Any cracking around them?

The way you did it is the way I want to, but the article shows a strap tying the two mounts together to add more surface area to glass to.
Those fuckers are laminated in there good. They?ll never have issues.

One thing I don?t like about the setup in the article is trying to laminate to aluminum. It?s not a good bond and will eventually have issues.
Title: Re: Fuel tank mounting
Post by: Grimpala on January 12, 2023, 06:13:00 AM: Quote from: JordanDangerfield on January 11, 2023, 05:22:02 PM
Those fuckers are laminated in there good. They?ll never have issues.

One thing I don?t like about the setup in the article is trying to laminate to aluminum. It?s not a good bond and will eventually have issues.

That makes sense. Are the blocks glued to the floor with anything or just glassed in?
Title: Re: Fuel tank mounting
Post by: JordanDangerfield on January 13, 2023, 07:55:27 AM: Quote from: Grimpala on January 12, 2023, 06:13:00 AM
That makes sense. Are the blocks glued to the floor with anything or just glassed in?
They?re glued down with peanut butter (resin, fumed silica, and blended CSM) and laminated over with two layers of 1.5 oz CSM and a layer of cloth (I forget the thickness on the cloth).
Title: Re: Fuel tank mounting
Post by: Grimpala on January 16, 2023, 10:38:04 AM: Quote from: JordanDangerfield on January 13, 2023, 07:55:27 AM
They?re glued down with peanut butter (resin, fumed silica, and blended CSM) and laminated over with two layers of 1.5 oz CSM and a layer of cloth (I forget the thickness on the cloth).

Awesome, thanks for all the info!
Title: Re: Fuel tank mounting
Post by: branconway on December 18, 2023, 10:31:53 PM: That makes perfect sense? has me thinking