to Kreem or not?

[theShadow]

Hello everyone! My 95 speed triple has a few spots of rust in the bottom of the gas tank, so I went to a local HD store and got a combo-pak of Kreem tank liner.
It seemed like a good plan, but when setting up the tank for cleaning I realised that theres is some kind of coating inside allready. Looks like a thin layer of orange paint, and it looks original.

Has anyone used Kreem in a tank with this coating? The people that sold me the treatment said it would probably be OK, but Kreem advises against coating over old coatings on their web pages..

[KitNYC]

I've read over and over in various places that either Kreem is bad and POR-15 is what you should use or that both of them are evil incarnate. There is a third product that recently made its way from aviation to the motorcycle shop, but i can't remember its name; that, of course, is the one I've only heard good things about...

All else aside, though, you're essentially painting the inside of the tank and, like all painting, surface preparation is critical. The factory coating has to come off before the new coating goes on.

Cheers,
-Kit

[KitNYC]

This was the new stuff I had heard about:

http://www.caswellplating.com/aids/epoxygas.htm

Again, I have never used it, just read good things about it on the Interent.

Cheers,
-Kit

[tealetm]

I kreemed the tank on the little CB200 I restored- that tank was really bad before hand so I guess it was worth it.

I didn't like the product though and wouldn't recommend it just for a few small rust spots.

[phil the greek]

I think I'd look out for a decent secondhand tank!

[Flying Custard]

I've used POR with no problems, but reckon like any resin it needs something to bite on. Smooth plated tank surface will probs let it peel eventually. Hence they supply acid for etching.

Wonder if the red coating is Red Kote or similar? mine has it too. Read good things about Red Kote but not used it, not sure it's even available to us over here.

Might be worth a grope up the top if poss, they usually rust up where the juice isn't / where condensation sits (might need the fingers of ET....)

[theShadow]

The fingers of ET...or flip the tank around and have a look trough the holes in the bottom..

The tank looks good in the top, but has two thumb-sized, rust spots in the bottom, and maybe rust in one of the seems. (hard to see..)

On one hand I am afraid the Kreem will crack up an float around in the tank, on the other I allready had rust and flakes of the old coating floating around.

The caswell stuff looked interresting, but all I could get hold off for now was kreem..

I am considerig to use little bit of the etching liquid in the bottom of the tank, to se what i does to orange coating. Probably wouln't have time untill next weelk dough.. Thanks for all help so far!

[HenryInFrisco]

I Kreemed my fat bobs on my 2002 Spec Const softail. It lasted 8 years until I sold it and moved up to a Daytona 675. Prep is everything. Take your time. Have the patience to do it right. It should last forever.

[95Trophy]

Hello All, I can't say yeah or nay on using Kreem but here's a solid process that I've used myself while restoring my '76KZ. The article was posted to the KZRider forum last year. I used the muriac acid and phosphoric acid combination with some small (1/4" or so) plated hardware store nuts for an abrasive and it worked very well. If you're careful and follow the instructions you should achieve successful results. Article and link are enclosed. Take your time and Good Luck! - Jim

Re:Z1R Gas tank cleaning? 11 Months, 3 Weeks ago
Rusty Tanks.
Written by KZCSI

Link: http://kzrider.com/index.php?option=...d=22&Itemid=11

Article:
Most recently, I've settled on a muratic acid wash followed by a dose of phosphoric acid as the best method, mostly because it always gets the job done and doesn't require a lot of physical effort.

To do the job you first have to decide if the tank has scaly rust or just surface rust. If the rust hasn't gotten to the point where it's scaly you can skip the 1/4" nuts, referred to later.

First, flush out any oily varnish that may be coating the lower regions of the tank with acetone or any of those engine degreasers. If you choose the engine degreaser flush the tank with water.

Remove the fuel level sensor. Seal it's opening with GOOD duct tape.
Remove the petcock and seal it up with an appropriate plug or capped section of hose. Dump 30 or so 1/4" nuts into the tank.
Pour in a pint or so of muriatic acid. Seal up the fill spout with GOOD duct tape.
While wearing gloves, old clothes and safety goggles. Agitate the tank for 10 to fifteen minutes. During this time you can monitor the pressure in the tank by watching the duct tape bulging at the fill hole. If too much pressure develops, carefully vent it by peeling the tape back than reseal and keep shaking.

Next pick a piece of concrete that you don't particularly care about. Remove the tape from the sender opening and fill hole and flush the tank with cold water. The acid that has not already been consumed will neutralize itself on the concrete. You're still wearing goggles and gloves right?

Now dry off the openings and reseal them with GOOD duct tape. This time pour in a pint of naval jelly, or milk stone remover or tile haze remover. These are all phosphoric acid formulations. Phosphoric acid is not as aggressive as muriatic acid and therefore is mostly a waste of time if you're trying to really remove rust. What phosphoric acid will really do well is leave the inside of the tank coated with iron phosphate, which is somewhat rust resistant. For this step you do not need much agitation. Just tumble the tank over several times and let it set for a half hour or so and then tumble it again. After about two hours of this and go back to the concrete slab, open the tank, drain it and immediately spray WD 40 into the openings trying to coat as much of the metal as you can. Now flush it out thoroughly with clean water. One more application of WD40 and you're ready to force dry the tank.

Back in the shop, prop a blowdryer so that it forces warm air into the tank and let it blow for an hour or more. Position the tank in different orientations during this process to make sure that no seam holds water. Once it's really dry you're done.

I used to say that the phosphoric acid step was critical to avoid flash rusting. Now, I still think it's a good idea for future rust resistance but since I started spraying WD40 into the still wet tanks, flash rust's no longer a concern.

I've probably cleaned a dozen tanks with some variation of the method I described and never damaged the exterior paint or eaten through the steel.

[KitNYC]

Are you sure that was posted 11 months ago? I could swear he posted that same article back when I was still reading KZRider every day.

Cheers,
-Kit