View Full Version : Need help with my sharkcat rebuild
Phatkat24
05-06-2012, 10:51 AM
Hi guys just looking around for some info on my shark cat she is a 23ft pre 1984. I need to know if the fuel tanks were fibreglass from factory ? Its the only thing i havent yet pulled apart. To get to them looks like the floor will have to come up. Is this a survey thing ? Any help would be great thanks... Scott
Noelm
05-06-2012, 11:31 AM
it should have stainless tanks, and the floor will have to come up, crap job, but not all that hard really, the tanks will be about 50-60mm below the floor, so a saw can be used, set to a depth only cut the floor, there will be cross over beams under the floor about every 500-600mm.
feral cat
05-06-2012, 11:54 AM
Yep noelm is right but just remember in the old days they used nails as well.When i pulled up my floor in the 560 sharky i used a diamond cutting blade with a grinder.Was cutting over the fuel tank and seen sparks everywhere.(proceeded with caution)When i got floor up and can see properly i realised i also had about 100ltr fuel sitting outside of tank in the well from cracked tank.Be careful.
Phatkat24
05-06-2012, 12:15 PM
The tanks are definatly fibreglass because i had to cut a hole into them not long after i bought the boat. They were full of stable foam which disintergrated over time and ended up through my fuel system allowing me to limp home on one motor. The boat at the moment is all but stripped for wondering if i should cut the tanks out. Any ideas on prices for stainless tanks ?
cormorant
05-06-2012, 12:16 PM
You an use a inspection camera an flush em as well so they are clean. Depends if ere is other reasons to pull up the deck You mention survey. If you are just talking about a inspection frinsurance they are just cheking the boat is in OK condition as opposed to a "boat in survey where it goes through rigorous checks on a annual basis so it is safe to carry passengers and be used commcially
A lot of old boats have already had the floors up in the past so unless you have a issue I'd start with a inspection port in the deck to check things out or use a fibreoptic or camera and have a good look under the deck.
Noelm
05-06-2012, 12:47 PM
well, that's news to me, I have never seen a Sharkcat with fibreglass tanks, and I have seen heaps of them with the floor and tanks out, all had stainless tanks (that rust out) and are held in place with spray foam stuff.
Noelm
05-06-2012, 12:48 PM
OH, and I have to ask, how did the foam get in the tanks???
Phatkat24
05-06-2012, 01:28 PM
Ill try and get some photos together for you guys. As for the foam i have absolutley no idea about it. Took it straight back to the guy i bought it off who was the local boat dealer in rocky and he helped out but had never heard of the foam either. I researched and all i came up with was they was a similar product in moto x bikes. Maybe the tanks had been done and the foam was added then. Again this is why im asking for help. Im finding out the hard way about old boats and the amount of owners that had a "GO" at doing her up.
cormorant
05-06-2012, 02:12 PM
I must be the odd one out . I've seen foam in tanks for some special applications. They are pretty special applications -, generally being shot at but sometimes where very large tanks are fitted , what was the history of your cat? Built to survey? Govt dept?
here is a modern example used in race cars
http://www.gmpracingproducts.com.au/fuel-cells/fuel-cell-bladder-fuelfoam.php
Locked under a deck in a inaccessable tank - no never but if the tank had access hatches and inspection ports - yep possible but it must be maintained and so must fuel quality.
Be interested in the photos of your cat as people will be able to point out any structural difference to run of teh mill cat if there is any.
Noelm
05-06-2012, 02:18 PM
I guess as a starting point, does the floor all look original?? or has it been cut to bits before? be sort of interesting to find the previous owners and try to piece together the history of the boat. A couple of photos would be nice.
The Woo
05-06-2012, 02:22 PM
well, that's news to me, I have never seen a Sharkcat with fibreglass tanks, and I have seen heaps of them with the floor and tanks out, all had stainless tanks (that rust out) and are held in place with spray foam stuff.
Me either, all I've opened have had stainless tanks too.
If she were mine I'd do it justice and lift the deck to inspect. Would be a terrible shame to tidy her up then soon after have a serious tank issue/failure.
I suspect the foam in your fuel is actually foam from inside the hull, definately not a racing fuel-cell type foam.
Another two bob thrown in, I'd be making stainless or thick wall alloy tanks to go in there, and fibreglass tanks don't cope with the increasing amounts of ethanol/alcohol in modern fuels.
The ex ASR 23' Sharkcat Dad and I bought years ago needed surgery to replace the tanks. It was a floating bomb waiting for an accident, the starboard stainless tank had cracked and half the starboard hull was full of fuel. The "seperate compartments" in the hull were'nt impervious to the fuel over time meaning the whole deck had to come up and it had to breath for considerable time to make safe before rebuilding..
cormorant
05-06-2012, 05:10 PM
FG tanks are fine if the correct resins have been used. It is a big " if " but interested to see the photos and know how old the tanks are. Most tanks made unless by a specialist in the last 20 years would not have the correct epoxy and resin blends used. Just had to be done right. Is it a diesel or outboard as the one in your sig is a outboard?
Just so you know a lot of tanks built for special purposes straight glass and others were stainless covered in glass so they would never fail and have less condensation and corrosion issues. . I'll be interested to see if yours are stainless covered with glass? When you opened them up was there baffles at all?
myusernam
05-06-2012, 05:36 PM
I have glass tanks (not a sharkcat) and they are really good, but once a few years ago before the rules on ethanol, I got fue in darwin from a different servo in the rear tank. It must have been ethanol and it ate away some of the glass lining and made the fuel turn to gooey shxt. for years thought the tank was buggered, but it settled down and is fine now.
captain rednut
05-06-2012, 06:25 PM
most new cats built today have alloy tanks in them and the last shark cat i cut open had alloy tanks. i bet that's confusing your theories?? inspection camera will solve the argument.
cheers Jim
Phatkat24
05-06-2012, 06:43 PM
OK so i just spent the afternoon cutting the floor up ... needs work a fair bit of rot in the timber around the tank. I took a quick photo of the tank before i ripped the timber around it 80866
Phatkat24
05-06-2012, 06:52 PM
Im not too sure about the original purpose of her. She is a central queensland boat so before me it had a pair of 140 johnno's, then i bought it about 2 years ago it had the twin 135 optis on it. 99 models, but basically ive had nothing but dramas with it but i have come to far to let it beat me. Ive sold the opti's now and got her all podded. Any help on the year or info on the build would help. I know it pre 84 because of the curved stem on the sponsons but that about it. 80867
boatboy50
06-06-2012, 12:20 PM
Hey Mate,
Your pics aren't working.
I've worked with cats made after about 1990, and they all to my knowledge had S/S or alloy tanks.
I'd be very interested to see the pics.
Darren
Darren
Mister
06-06-2012, 12:39 PM
Sounds like a boat that had added fuel capacity and had to use aircraft type fuel core due to the capacity? Have you ever filled these tanks from scratch to full? Are there any signs of old pod arrangements (bolt holes) in the stern. What name was it previous?
Phatkat24
07-06-2012, 09:27 AM
Sorry about the pics not working ill try again to attach them... as for the tank volume i believe that they are 300l. When i bought the boat it was call Phatkat but previously it was called Topcat.
Phatkat24
07-06-2012, 09:33 AM
80903Photos of the floor being cut out exposing the top of the tank
Noelm
07-06-2012, 09:46 AM
photos still not working, there is a link in the help section that explains how to attach photos, it's pretty easy to follow, from my hazy memory, most 23' had 205 litre tanks (the old 44Gallon drum) so perhaps yours has been enlarged at sometime, but then again, my hazy memory could be way off
For posting pictures use the Advanced Reply Box, the Quick Reply Box doesn't work.
Phatkat24
07-06-2012, 10:27 AM
809118091080909Hopefully this time it works...
Noelm
07-06-2012, 01:56 PM
those tanks do not seem to be in the right place, the filler for them was a lot further back down the gunnel/deck that that one, maybe it has been modded and the tanks moved forward a bit, at a guess, I thing they would have been in the compartment between the tanks where they are now, and the storage boxes in the rear, where those two round holes are cut.
Mister
07-06-2012, 02:23 PM
Those tanks were specially made and I reckon they have had ethanol fuel in them at some time which ate the inards out of the fuel cells?
The Woo
08-06-2012, 09:45 AM
Yeah they're a long way forward.
Standard tank position was in the compartment ahead of the kill tanks, and aft of where they are now. Are there any tank in that area now, where the inspection ports are? Any hoses eaither for filler or feeds going through a bulkhead anywhere to fill a tank further aft?
I remember "Top Cat". If it's the same Top Cat she's worked central Queensland waters as long as I can recall and I'm 37. I'll ask my old man too, but I think she was a pro reef fishing boat for a lot of years, and likely needed the range that bigger tanks bring. Given the weight they'd carry in ice and fish she may well have been built or modded to have tanks further forward.
*** Also, it may be a trick of the eye, but in the cockpit area, is the area between the inner coaming edge and the floor been filled? If so, what's in there?
Phatkat24
08-06-2012, 01:59 PM
Thanks so much for the info guys the tanks are now out of the boat and after a quick measure they are 400L each. Alot more than i need thats for sure. As for the history of the boat it would be great if anyone comes up with more info.... I just filled in the area next to the helm because they had a hidous alloy box that the controls were mounted to so i just filled it in and ill cut it out later to what ever size suits. If you guys want more pics of her let me now and illl throw some up. Thanks again.
The Woo
08-06-2012, 02:10 PM
Always keen to look at pics of other people's projects mate.
I've spoken to my Dad, he doesn't remember any more details than I do sorry. He actually thought it used to be red and white? Any trace of red on her?
What are you doing with the tanks?
Where are you mounting the controls? Lots of guys seem to mount them up on the dash at chest height which I'm not a fan of. I like them (and the trims, rewire/reswitch if need be) down beside me at waist/hip level so you can really work the throttles properly in a sea. Near impossible to be smooth on throttles when reaching forward with your body weight heaving for and aft.
I think there's another 23 in my future once the current project is complete. Love them :)
Phatkat24
08-06-2012, 07:13 PM
There is a trace of red on the front under the anti foul so might be the boat .. Do you remember what powered her then ?
As for the tanks ill be replacing the fibreglass tanks with either stainless or alloy need to do some research, ill decreace the volume but.. Ill be mounting the controls on the side so i can have finger tip control when underway. Ill put some more photos of the project up tommorow it will be a new boat when im done !!
Mister
08-06-2012, 07:53 PM
Any comments if those fuel tanks have had ethanol in them in recent times? Those fuel cells should not have failed otherwise.
Phatkat24
08-06-2012, 08:30 PM
if your talking about the foam that was in the tanks i personally never put any ethanol fuel in the boat. Im trying to track some pictures of the foam it was nearly 2 years ago so its proving hard. The tanks are now out of the boat and a in pretty good condition.
Scooter101
09-06-2012, 08:15 PM
Hi Phatkat,
I have just completed a reno on a 23ft Sharkcat around the same age and condition, and one was aluminium and one stainless. Both were 200lt and there were extra 100lt tanks aluminium installed in front of the main tanks, where yours are shown in your pics. I think one used to be a water tank or both were. Tanks were pressure tested and good. Was an interesting project but all turned out good. Good luck with it, always ends up costing heaps more than you budget :)
The Woo
10-06-2012, 11:20 AM
There is a trace of red on the front under the anti foul so might be the boat .. Do you remember what powered her then ?
As for the tanks ill be replacing the fibreglass tanks with either stainless or alloy need to do some research, ill decreace the volume but.. Ill be mounting the controls on the side so i can have finger tip control when underway. Ill put some more photos of the project up tommorow it will be a new boat when im done !!
If I had to say what engines she had in the 80's from memory I'd say OMC ('rudes or Johnos) V6's.
Re tanks, given they're a bastard to get to , I'd suggest having some thick wall (thickest you can afford) alloy tanks built, then have them painted by a pro externally. We chose Jotun paint used for commercial fuel and acid tankage for the new 450 litre tanks in our current boat. I suggest alloy (thick material though so no flexing) as I've just seen too many stainless tanks crack. Usually from tank walls flexing and work hardening beside welds.
Also, I suggest pressure testing yourself prior to painting (to 15/20psi max or you'll stuff it) ...... Just so you KNOW they don't leak before being sealed in the boat. (trust nobody basically, Murphy says if you do, it'll bite you).
Long story but the tanks we just had made both leaked.... breakdown in comms in the manufacturer's workshop apparently, everyone thought someone else tested them. Thankfully I checked for myself prior to installing them under the new $10k teak deck! To their credit they got them 100% in the long run and didn't charge a cent given the amount of heart ache.
Phatkat24
11-06-2012, 06:31 PM
Ok floor is up up now it looks like the last time she was done up someone has put in hardwood stringers with no resin sealant on them looks a bit dodgy. But other than that everthing else look pretty good. Had a ball pulling all of the foam floatation out filled my trailer easy. What do new boat manufacturers use for floation these days ? This shit looks like foam-a-fill .....
Ill get some quotes happining tommorow for alloy tanks ill decrease the volume to 250 - 300L each. Rifen boats in rocky did a great job on the pods so ill give him a go at the quote. Any ideas on average prices ?
Also what does blasting and painting the tanks prior to install achieve ? Is it just to stop corrosion ?
Phatkat24
11-06-2012, 06:38 PM
8114081139The cat how i bought her terrible pod set up. And the new pods by Rifen boats in Rocky
The Woo
11-06-2012, 07:51 PM
It probably WAS foam-a-fill! Horrible shit that soaks up all the water around it.
These days they use closed cell foams.... well, the GOOD builders do anyway.
Etching and painting the tanks just gives them an extra barrier against corrosion.
Prices seem to vary wildly. I reckon if the value seems ok and you're happy they'll do a good job (and check they don't leak), then that's ok.
Mister
13-06-2012, 07:53 PM
Advise for some, if you don't know what you are talking about best say nothing, assumptions and wrong info give misleading info and highlight what you actually don't know.
Jarrah Jack
13-06-2012, 08:10 PM
Advise for some, if you don't know what you are talking about best say nothing, assumptions and wrong info give misleading info and highlight what you actually don't know.
It doesn't get better than that...........
The Woo
14-06-2012, 09:19 AM
Maybe I'm a simpleton, but Mister, are you insinuating I'm sharing incorrect info or knowledge? If that comment is for me, please sir, correct me..... :-?
Phatkat24
20-06-2012, 04:03 PM
I wouldnt worry about him mate seems like a ###### who justs rolls up and seez that...... ive decided to keep the fibreglass tanks and modify them. Been having big discussions about the way that alloy and stainless tanks just wont suit this application. Therefore ill freashen up the glass tanks and go from there, Ill keep you posted with info of the build thanks again for your help.
Mister
20-06-2012, 05:43 PM
At least this ###### knows the difference between what is right and wrong :) Really not my problem what you think about this.
And also have some advise for you which you can action or ignore at your own risk. Use those same glass tanks then make sure you ensure they are internally "controlled".
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