Sanding a Fastback Tank

I have a 69 Fastback fiberglass tank that is in original condition that has some stains on the gelcoat. To clean the stains I want to start with 1000 wet paper and progress to 2000 wet. After that I would compound buff and follow up with a polish buff. Has anyone one else done this with an early tank and what were the results.

I haven't tried this on a Norton fiberglass tank, but I have done lots of fiberglass restoration on older boats. Same principles apply. In theory, what you are proposing should be possible.

A few considerations:
-You mentioned that there are "some stains ON the gelcoat". Actually, there are "some stains IN the gelcoat". Gelcoat has a fairly high level of porosity, and the older and weathered it is, the more porous it is.
-You will need to sand down INTO the gelcoat layer to remove the staining. I don't know how thick the gelcoat is on the Norton tanks, but the thicker the better for your purposes.
-I doubt you will be able to accomplish what you need starting with 1000 grit. Doesn't hurt to try, but don't be surprised if you are working at the 400 level to begin with.
-The colour of the gelcoat will be faded, so as you sand out the worst part of the stain, you will notice that you get a deeper original colour, but only where you sand. You might get lucky, but you will probably need to do the same processes to the whole surface of the tank to get an even colour.
-Be careful when you are working near corners, as the gelcoat will burn through corners much faster than flats. Gelcoat is quite soft, softer than fiberglass, and softer than paint.

Stephen Hill

Modern fuels will eat a fibreglass tank quicker than a dog will eat a rat.

So before you start, make sure that the stains in the tanks are not the dreaded fibreglass rot, then have a go at sealing the tank before you spend any energy on the external cosmetics.

Personally I would throw the fibreglass tank out and replace with Indian made steel ( will also need sealing) or expensive alloy from likes of RGM.

The Emgo Fastback tank from Taiwan sold by several dealers is the best option, better quality than India and not as costly as alloy.

Do Emgo make a fastback tank?

I've seen the roadster ones and would really welcome a decently made Fastback tank

50vincent said:

I have a 69 Fastback fiberglass tank that is in original condition that has some stains on the gelcoat. To clean the stains I want to start with 1000 wet paper and progress to 2000 wet. After that I would compound buff and follow up with a polish buff. Has anyone one else done this with an early tank and what were the results.

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I buffed out the gelcoat very nicely on my original tank.( See my other thread ) You might think its gelcoat but it might be paint. You can use the tank , but you cannot store gas in it. It should be drained and blown dry after use. If its delaminated or starting to, you are kind of screwed, short of taking out the bottom reglassing everything up and reattaching it.

Sorry Roadster is the Emgo, no Emgo Fastback, only Indian and Alloy.

http://www.burtonbikebits.net/Tanks.htm


Have run one of these for years , again draining the tank when its gonna sit for a long time

I believe that the Indian Fastback tanks for sale are advertised for later year Fastbacks than my 69. Has anyone fitted these tanks to a 69?

Thanks

John

The Burton Bike ethanol resistant FIBREGLASS tanks have been out of stock for as long as I have been looking for a replacement tank.

I can only speculate that perhaps it was not as resistant as planned. I also think that the tank that had rotted on my bike was a burton bits tank.

Come on EMGO start making Fastback tanks

chasbmw said:

The Burton Bike ethanol resistant FIBREGLASS tanks have been out of stock for as long as I have been looking for a replacement tank.

I can only speculate that perhaps it was not as resistant as planned. I also think that the tank that had rotted on my bike was a burton bits tank.

Come on EMGO start making Fastback tanks

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Mine is OK, although I did have it coated when it was new, and again I never store gas in it

50vincent said:

I have a 69 Fastback fiberglass tank that is in original condition that has some stains on the gelcoat. To clean the stains I want to start with 1000 wet paper and progress to 2000 wet. After that I would compound buff and follow up with a polish buff. Has anyone one else done this with an early tank and what were the results.

Click to expand...

To answer your question without prompting you to convert to a metal tank: when I bought my '72 roadster it had the original fiberglass tank, signal red. My plan was to convert to a production racer. Just for fun and I had the time, I started as you suggest sanding with fine wet sandpaper then finished with Tripoli then white fine polish on a rag wheel. It came out so good I scrapped the PR plan. This was in 1998. It now looks great hanging on the wall and I'm using a metal tank.