Fuel Tank Relining - Your Opinions Please

[BPT]

If I was going to repaint a tank, should I consider relining it no matter what (since I won't have to worry about ruining paint and whatnot)?  Or would you only bother if the lining was really bad?  This one has some scratches that are visible from the filler hole. Unfortunately I don't have one of those inspection cameras to get a better view of more of the inside.
So what would you all do? Do it since you're already doing other stuff and then it won't need to be done again for a long time?  Or, if you think the current lining is OK, just leave it alone, save the cost and effort?

[Bob_Roller]

If the interior of the tank is not rusted, I'd leave it alone .
I would remove the fuel valve about every 6 months to see there is a lot of liner chips in the area .
If you're getting a lot, may be time to reline the interior .
I've relined three tanks not a difficult job .

[BPT]

Thanks Bob Roller.  What you see in the pic is all I can see. No obvious rust, just those scratches. I didn't know if I should worry about the scratches becoming a potential for peeling later.
I was thinking the same - if it's ok now, just leave it.  But then I was thinking of further down the road, once it's painted, will I wish I'd done it first.

Years ago I'd seen some cheap scope cameras that you could use via phone and they had decent reviews. I might see if there's a current one out now that's decent and not to expensive.
Thanks.

[dogshome]

Mine was slightly worse. I did pull red liner flakes out of the fuel filter initially. I then gave the thing a good washing and have not had any issues since. I didn't find any rust during the wash but the valve main/reserve tubes were well rotted. I soldered brass replacements once I'd cut the originals down.

I got my torch down in the seams at the bottom and did not see anything too horrific!

Nothing else has dislodged since (2 years), but I do ride the bike at least once a week. Fill up maybe every 1-2 weeks.

[Tony Smith]

 Cheap endoscope cameras available from Banggood.com, choice of visible light, IR and UV (visible is best for peering into tanks).

After having tried many tank lining products I have settled on an Australian product Red White & Blue (redwhiteandblue.com.au). No need to remove all of a liner, the bits still adhering can be left in place, doesn't shrink and will fill a very large hole (I have put this to the test on an old stationery engine tank I thought I would have to weld). Also does not damage paint (within reason).


I will just throw in a tip I was taught that is for any new liner. When you have finished and done what you can to get excess liner out, roll the tank on its back to let the liner harden. Doing this means that any thick "gobs" are in the top of the tank, out of the way. I had to spend half a morning boring through epoxy so that fuel could get to the tap once, and as luck would have it the tank in question had a large rectangular protrusion into the tank. Many hours taken to carefully file the expoxy away once the initial hole was drilled. If it had been on its back that would not have happened

[BPT]

Thanks for the tip Tony Smith. As for that liner you mention, I'll have to see if we have an equivalent in the US. Something that doesn't require removal of the other one would be great.

As for cameras, I ended up getting one the next day. Still trying to figure out how to maneuver it but I managed to get more shots of the inside and it looks pretty good. Most of the scratches appear to be the ones in the pic above, right below the filler hole. I guess someone was trying to do something right there, or maybe had it upside-down sitting on a pole?
After seeing more of the inside, I now feel more comfortable leaving it alone. However, if I could find a product like yours that could go over what's already there, I'd do that to fix the scratches.

Thanks for the replies.

[BPT]

This is the worst area, right below the filler hole.

[BPT]

The rest looks pretty good. There's this one spot where a chunk is missing.

[BPT]

Otherwise, not too bad.

[Luca]

I first tried the POR-15 tank lining kit, but it wouldn't strip the remainder of the old liner.  I ended up stripping the liner with hardware store phosphoric acid (concrete prep and etch).  That stuff will allow the tank to flash rush very quickly, but it wasn't a problem, as I then treated the tank with a product called OSPHO.  It's phosphoric acid based, but it doesn't cause flash rust like straight phosphoric and it seems to do a better job converting rust into iron phosphate.  If I spring a leak I'll go back and try a lining product again, but until that day comes I'd rather not encapsulate any rust that made it through the prep work; it's hard to verify prep work inside a tank.

P.S. During this process I protected the exterior paint with good ol' Vaseline.  If you leave it on forever it can damage the paint, but for a few days you'll be fine.  In hindsight I should have started with some fresh wax on the paint as well.

[BPT]

It's definitely the stripping process that seems to be the biggest pain.  Looking at what I found in these photos, I think I'll leave it alone.  I wish I could find something like what Tony used that I could put over the existing liner that would take care of the scratches but I couldn't find that product being available in the US and not sure about an equivalent here.

[Tony Smith]

I am pretty sure that Redwhiteandblue do post to the USA.

Also, the chemical to remove old BMW liners is Acetone.


A new near equivalent of the original liner is Redkote which I used successfully a number of times before going to the Australian product.

[mrclubike]

BPT's tank liner is in like new condition compared to mine
My liner has been flaking off since I have owned the bike (2014)
I have had  no issues with the the filters or carbs clogging up
I do run one of the little 90deg in line filters for good measure
A;so the bike rarely sits for more than a month without being ridden 

Now watch I just jinxed myself and it will clog the next time out   

[mrclubike]

Otherwise, not too bad.

Honestly I would not bother with relining that tank

[dogshome]

I swapped the fuel tap on mine at the weekend. I'd repaired the original with a kit and that worked initially, but every once in a while it would 'run' from the tap handle itself. Not just a drip, but a fairly good leak. Rotating it would invariably solve it until the next time it randomly decided to do it again. Sometime months later.

Anyhow a big lump of red liner was in the reserve position and various other red and rusty articles came out where the tap was. Some 3-5mm bits that looked like they'd been hanging on for a while, not a load of red dust and water emulsion though.

If the tank looked like the one in the original post, I'd also not be worried. I'm not overly excited about mine, although obviously worse, as the fuel is 'clean' but will put it on my long term hit list.