26. Assembly... sealing tanks...

A blow by blow photographic account of chopping from stock to chop... This projcet has been given its own forum due to the large number of photos it contains making uploading slow for those of you still on "dial up".
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Prof
Founder, Choppers Australia
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Joined: Sat Oct 22, 2005 3:54 pm
Location: Willunga, South Australia
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26. Assembly... sealing tanks...

Post by Prof » Tue Apr 10, 2007 7:29 pm

Sealing the petrol and oil tanks...
When welding fuel and oil tanks with MIG or gas, it is reasonably difficult to avoid some pinhole leaks. Rewelding these points can take a lot of time and the extra heat often spoils your job.... so POR15 to the rescue. I've used this on quite a few tanks and not had a problem with leakage even after 30 thousand plus k's.

You can get POR15 from a car paint supplier. It is expensive at $60 a litre, but despite what it states on the can, can be reused many times. The process is to pour the full can into your tank, swish it around and pour it out again. A four gallon tank does not use a lot, but 500ml is the minimum amount for a good cover.

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Make sure your tank is clean inside and free of loose rust. Gravel and water make a good abrasive. POR15 make a rust sealing product to use prior to their sealer. Use it if you have a very rusty tank.

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Next job it to seal all outlets. This is part of the standard Harley tap... with a piece of broom handle, sanded slightly smaller and screwed in (Left Hand Thread)plus a rubber washer made form a piece of m/cycle tube.

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Oil tank has had a new drain set up made so it also needs sealing. Outlets are blocked with ¼" bolts and a bit of rag. Filler plug is covered in gladwrap with a bit of duct tape holding it on.

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Once POR15 has been put in and thoroughly swished around, the tank needs to be drained for 30 minutes. Make a hanger that will tilt the tank on the right angle so ALL excess sealer drains out through outlet BEFORE you put the stuff in!

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Mix the POR15 very thoroughly as it will be pretty thick on the bottom. YOu can see some lumps that did not mix, in the funnel if you look closely.

Pour the sealer into the tank. It's messy stuff so have plenty of clean rags on hand and perhaps use some thin gloves, so you don't get sealer on the nice paint work. It doesn't come off easily.

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Use the ENTIRE contents of the can and roll the tank around very carefully to ensure the whole surface (and every corner and weld is coated)

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Drain back into the tin for 30 minutes. Make sure the threads are clean of sealer and in the case of the oil tank wipe and blow out the outlet pipes. Clean around the filler spouts. POR 15 should not be exposed to petrol for 96 hours.

Job is done and if your welds are strong, even on a Harley, your tank shouldn't leak. I'll let you know for sure when I get up to the Gold Coast!
Chopit'nrideit... Prof

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