'09 Subframe fuel tank ??

Great piece of work Sabink !
Not something i would tackle without help.
How much extra fuel does that section of subframe hold for you ?

Cheers,
Nick

NKW570 said:

Great piece of work Sabink !
Not something i would tackle without help.
How much extra fuel does that section of subframe hold for you ?

Cheers,
Nick

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It's about 3.8 - 4 liters

DaleEO said:

okle said:

looks great, sabink!

two questuions come to mind (maybe i just dont understand)

1. how did you fix the weak spots?
2. whatfor is the plug you added in the last 2 pictures?

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I was wondering too okle, I just re read his post and it was clear. He used the plug to fix the weak spots where it was leaking fuel.

Dale

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That's right. It was only leaking from the left weak spot on the picture. The right one was not leaking, and seems to me strong enough to hold the fuel without problems in the future. You can easily check if your tank also has these weak places with a flashlight from the other side.

Fantastic report and pics, I am sure this will influence a lot of ppl to do something themselves.

Question: Is it possible, or did it cross your mind, to perhaps put some fibreglass patching, or some sort of melted plastic on those weak spots where you put the plug ? Either in conjunction with using the plug, or just reinforcing on its own.

I would say fiberglass patch would be the way to go to repair any weak spots. I've repaired large Bomag roller plastic water tanks among other plastic things for years. Find your weak spots and use an angle grinder with 36 or 24 grid to carefully ruff up the area and beyond over an inch. Lay your patch with resin and tape off the area if needed to prevent your fiberglasss from hardening on a smooth surface. You don't want it to start lifting later. Do it right and have peace of mind later knowing you have a thicker wall there.
Pollo

I have had some bad experience trying to weld plastic, especially fuel tank plastic, and I do not want to use this method.

Thanks for the idea. I like the resin idea, I will experiment somewhere on the sub-tank, where there is a lot of material and if has strong adhesion I will use it on the second weak spot. The first one is fixed, as it was about 9mm diameter, and I drilled it all.

Gazza said:

The Loctite guys at this years Dakar rallye in South America were using the perfect 2 pack material there I reckon, not sure what the name is but saw them repair many such items with it during the course of the rallye, including plastic fuel tanks, it was black. I will check and see what it was.

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It will be great, if you can get the product name or number!

I have some 2 part plastic ahesion products. They are at work. I'll try and remember to get the name for you. They are good for certain applications such as sandwiching plastic and fiberglass panels together. Remember that you still need to sand the areas before applying. In my experiance they do not work as well for repair of cracks, broken pieces or build up as we are talking here. The whole piece is more libel to lift up than fiberglass. Thats why for heavy repair work I went with fiberglaass a long time ago .
I lowered my seat a half inch over 1 year ago with fiberglas. I cut off the plastic hooks underside, grinded them down and fiberglassed them back on. It still holds like the day I did it and you know that you need to hook the seat under those metal frame tubes
Pollo

For those of you interested in the 2 part plastic adhesive here of the types I use at work.
3M Automix E-Z sand rigid parts repair kit 5883A and 5883B
Work time is 10 minutes Clamp time 30 minutes and Cure time 4 hours
I have used this one for scratches and gouges on auto bumpers. It adheres well and sand into the esisting plastic good. Also it is more flexible than spot putty which you need for that type of plastic repair.
The directions for use say that it is used to repair fiberglass enforced plastics and joining fiberglass and plastic rigid parts.

The one we use more often and I think is better is the 3M Automix 2 part 8268 adhesive SMC Fiberglass 10
Its a 10 minute, 30minute, 60 minute product as I said with the other Kit but I believe is stronger.
Note that these products state that they are used to repair Fiberglass re-enforced plastics meaning that the major work is accomplished with fiberglass.

pollo

As I 've looked and read closer on the pictures of the weak spots I have been thinking about the best repair. Garbage bag
thin is scary thin and with this type of project you probably do not want to grind through when you repair it. You may need the hand sand in those areas to scuff it properly and also because the grinder will not get in the corners like you want. What you also want to do is to extend your repair area into the thicker plastic where you can grind deeper. If you grinded through you can still be successful even though you should try not to. It also would help if I saw this piece in person as I woud know exactly how to do it.
Fiberglass works good if you prepare your area right. Smaller patch areas don't work as well as larger and since there are 2 problen area you might want to join them in one large patch. It's an option worth considering and you would need more griding of course.
Just make sure the weak areas are well into the patch . You could make it strongest and look good also by using Fiberglass Mat and Fiberglass Cloth. Cut up the Mat into small pieces of various sizes. Lay it down first into the grind with your resin and overlay on top with a piece of cloth or 2. The cloth is like a blanket and also looks cool on a finished surface. Wipe all excess resin before it dries off of any ungrinded surface. The subframe should be set up on a bench or somewhere where the resin will flow in the right areas
Pollo

Gazza said:

Ok got the low down on the Loctite wonder goo stuff I saw at Dakar.

Turns out it's a strange one, Loctite themselves don't distribute it here in Australia, but most Ford dealers and a lot of truck supply places carry it. The product range is called TEROSON, and the one we would have seen at Dakar is most likely TEROKAL 9225.

The guy in Loctite Aust who looks after it (even though they don't distribute it ?) is John Bateman, whose mobile # is 0400 813 850.

I would say this would be the perfect fix for reinforcing any weak areas on the subframe fuel tank based on what I saw at Dakar.

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confirmed. see the promotional website of HEnkel. http://www.henkel.com/cps/rde/xchg/henk ... E_HTML.htm

Subink,
The concern is that your plug covers the entire weak area or that it doesn't crack or splinter from the hole causing a leak.
If it does begin leaking the answer may not be to remove and just keep repluggimg it, but to repair over the plug.
In that case, I would remove the plug, grind and prepare for glass, re-seal the plug back in the hole and glass over it.
Pollo

Thank you for the recommendations. The plug was the solution I can make "today", as I wanted to ride with the tank tomorrow
I never knew about the products you recommend to glue it, it's great information! The plug is holding fine for now, as it lies on o-rings, so cracks are not likely to appear. One thing I had to do is grind the plastic with fine sandpaper to polish the rough surface where the o-rings lie.

I discussed this topic with my dealer today, he said there might be a problem with the plastic subframe part holding the new tank, that the weight of the tank might be getting to heavy for the rest of the construction, i'd say since i am only 75 kilo's adding 5 kilo's in weight on my self would be the same effect, any thoughts on this?

I do not think so. If 4 kilos is a problem to the subframe, then what will happen when I sit on the back with my 105 kilos? About 1/3 of the seat is on the subframe. Also most of the fuel is in the front side if the subframe, where we have 5 bolts.

I think the biggest issue may be if we hit the muffler hard enough to brake the subframe on the muffler mounting points. That is why there must be a valve between the fuel tank and the subframe tank.

i'd say you're absolutely right.

..actually you are saying i have room for an extra 30liter tank

Has anyone got any further with the subframe tank, if so has it been succesful.

evo01 said:

Has anyone got any further with the subframe tank, if so has it been succesful.

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I have got about 500km on my setup and it's holding fine so far!