Topic: Holes in gas tank, Red-kote?

[kawabunga]

Hello all,
I'm new here, I just started my first restoration project and am seeking advice.
I am bringing a family bike to life, a 75 CB550F.  It's been in the family since new, my grandparents originally purchased it but it's been sitting for quite some time.  I dug it out of the shed this fall and started tinkering.  I've already got it running after sitting 21+ years!
On to my order of business.. the gas tank is quite rusty inside.  I cleaned it out with nails the best I could and rinsed it.  At that point I discovered numerous pin holes in the bottom of the tank.  I was originally planning on doing a tank sealer but it's my first time and I REALLY wanted to save the original paint.  It's got nicks and dings but overall is quite good for 38 years old.  It has character in my opinion.  Anyway, not feeling optimistic about it, I took it to a local tank restoration shop that had great reviews, they have their process of cleaning and prepping that involves a mild media blast to loosen the chunks of rust.  They made one quick, light pass and discovered many more pinholes on the side of the tank, even as high as the Honda emblem.  Some about 1/32in.  I told them to stop.
My question is, is this tank savable at this point?  They won't do just a sealant for liability reasons, they want to strip it and weld the holes.  Can I coat the inside of the tank and tape the holes to save the paint?  Will Red-kote do a well enough job to contain the fuel with that many pinholes?  Can I do numerous coats for extra protection?
Did I screw myself over here by having it blasted?  One of my colleagues was saying I should've just coated it without blasting since it adheres to rust anyway.  Now I'm feeling pretty dumb for not just trying it...
Is all hope lost?  Are there any glimmers of hope?
Any insight is appreciated.
Thank you,
kawabunga

[calj737]

Red Kote is the answer. You need to thoroughly clean the inside of the tank (even de-rust it) for best results. Red Kote doesn't prefer rust, it prefers clean metal.

Thoroughly wash the inside tank with soap/water. Rinse well. Thoroughly rinse tank with Acetone afterwards to evaporate all water and soap. Then add Red Kote. Use the whole container is you wish, but be very diligent about SLOWLY rotating the tank to cover all areas. Drain the excess Red Kote and let cure.

For best results, cure it in a temp-mild area for several days or at least until you can no longer "smell" the Red Kote.

Caveat: wherever you have holes, the Red Kote will seep through. Protect the outside of the tank in those areas, lest you will have red buggers everywhere! You can cover the outsides with Painters Tape, or some type of plastic, don't use duct tape. It will never release from the paint or RK that seeps through.

Afterwards, wipe your tank down on the paint with Denatured Alcohol. Should clean up fine. Multiple coats are not advised nor beneficial with RK. One proper coat with sufficient rotation will cover the whole darn liner.

[davesee]

i've never used red kote, so i can't comment on it's ability to bridge holes. i have used caswell epoxy a few  times. my daily driver has an old 450 tank on it that had a number of holes, some bigger than 1/8". i sealed the tank with caswell (using about 50% more than the directions called for, which most people recommend for best coverage) and i am leak free after two years and about 8 000 miles. i put masking tape over the holes to bridge them, and there was no apparent damage to the finish.
the caswell epoxy will bond strongly to clean or rusty metal. my tank may rust now from the outside in, but at least i'll have a clear epoxy gas tank then, which would be kinda cool.

i can't recommend caswell highly enough. i was blown away by the job it did on a tank that was pretty far gone.

http://www.caswellplating.com/restoration-aids/epoxy-gas-tank-sealer.html

[MoMo]

I have seen two bikes with Redkote fail, fwtw...Larry

[kawabunga]

Thank you for the responses!  Perhaps there will be hope.
calj - awesome to hear it worked so well for you!

Davesee - 1/8" you say?  That's impressive!  Any photos by chance?  Just out of curiosity.

MoMo - I'm not 100% settled on red kote necessarily, it's been recommended to me by a few people that have already used so I thought it would be a good starting point.  Also read many good things about Caswell and POR-15.

Like I already mentioned, saving the paint was my biggest concern (other than it functioning like a gas tank of course).  I am prepared to hang the tank on the wall if it is not savable since I'd rather have it as a keepsake than strip it down at this point.  It may be a silly thing to hold onto but I enjoy the nostalgia of it; it reminds me of my grandparents.  Hence my concern of any of the tank sealant leaking out and ruing the paint.
So, painters tape will do a well enough job of holding it in?
If it's very visible after coating can you put a dab of touch up paint on the sealant?  Or will that ruin the sealer?

Thank you,
kawabunga

[ekpent]

The latest issue of Motorcycle Classics just had an article about tank sealing and hole repair. Some pretty good tips on protecting the tank. I make a good plug or cover with rubber gasket to block the petcock and an expandable rubber plumbers plug (nut on top) for the filler hole to make a nice tight seal for the swishing.
  I have used Redkote and have a couple of observations. One thing I have noticed is that the red color has changed and the coating looks like it has thinned with prolonged use. It will turn your gas red but the bike has run well and nothing has failed. Best thing is to try and not use any sealer but in your case its a good repair option.
  Not sure if this attachment will be readable but can send bigger,better pics to your e-mail.  Eric

[Duanob]

i've never used red kote, so i can't comment on it's ability to bridge holes. i have used caswell epoxy a few  times. my daily driver has an old 450 tank on it that had a number of holes, some bigger than 1/8". i sealed the tank with caswell (using about 50% more than the directions called for, which most people recommend for best coverage) and i am leak free after two years and about 8 000 miles. i put masking tape over the holes to bridge them, and there was no apparent damage to the finish.
the caswell epoxy will bond strongly to clean or rusty metal. my tank may rust now from the outside in, but at least i'll have a clear epoxy gas tank then, which would be kinda cool.

i can't recommend caswell highly enough. i was blown away by the job it did on a tank that was pretty far gone.

http://www.caswellplating.com/restoration-aids/epoxy-gas-tank-sealer.html

I have to throw my hat in for Caswell too. I just lined a 550F tank that had some pretty bad pinholes, maybe more like ballpoint pen holes.

Caveat: So far so good. it's only been a month. I put the first gas in it a week ago and I am on my second tankful. I've used non-ethanol only gas so far. It seems to be working, no leaks or failing of the liner. Just follow directions to a T.

[ohiocaferacer]

A few months ago I sealed a GS1000 tank with the Caswell.....AWESOME PRODUCT!!
Tank has had gas in it now for a couple months with no issues.

Here is a reply with pics I posted in another thread.
http://forums.sohc4.net/index.php?topic=125089.msg1422400#msg1422400

[ekpent]

In the article I posted they also used the Caswell product.

[hillcountrymac]

I've coated 2 tanks with Redkote with no problems.One has been probably 7 years on an old honda 100 and it is just fine.It didn't have any holes though so I can't comment on that.The good thing about Redkote is they sell it at O'Rieilly,s and there is no mixing if I remember right.

[Geeto67]

when I worked at a radiator shop we used Kreem and Redkote (caswell hadn't been invented yet, or my boss didn't buy it - this was also pre E10). For light stuff we used kreem and hated it because it failed often enough to be a headache.

Redkote we used for industrial jobs and it worked. Flat farking worked. The only issue we had is if we didn't get good coverage we would have to burn it out because no chemical would breach it, and even then it was heating it and then wadding it into a little ball with needle nose till we could get it through the cap. Now being a rad shop and working on isdustrial equipment we didn't care for paint - we would boil the tank in MEK for a while to de-rust, then pressure test, and then braze over any pinholes we saw. Then we would rinse with, I think, laquer thinner, blow air through and begin the coating process. Never had one fail. In fact at one point I built a fibergalss tank, but I used the wrong epoxy and it wasn't fuel proof. To save it I poured red Kote in it and when the tank finall cracked away I had a semi flexible fuel tank bladder sitting on the top rail of my motorcycle. Until the shop closed they used to use it as a demonstration of what red kote is.

Redkote is like any liner - it is all in the prep. If there are failures, it is because there wasn't adiquate prep.

[Magilla]

I've used RedKote and its good stuff but if you have holes that are 1/32 in diameter and you have a lot of them it is my recommendation that you buy a new tank.  Keep this one as a keepsake or make a cool lamp for your shop.

Having a failure with fuel leaking onto a hot motor or blowing back on you while your riding is not worth the risk.  There are plenty of tanks on eBay it one of them may save your life.

[kawabunga]

Thanks for all the info!  Much appreciated.
I'm still not sure what I'm going to do with it yet.
I've already arranged the purchase of another tank so I might just go that route.

Thanks,
kawabunga

[Duanob]

A few months ago I sealed a GS1000 tank with the Caswell.....AWESOME PRODUCT!!
Tank has had gas in it now for a couple months with no issues.

Here is a reply with pics I posted in another thread.
http://forums.sohc4.net/index.php?topic=125089.msg1422400#msg1422400

Curious: Are you using ethanol gas? I've heard that is what eats tank liners and makes them fail. Caswell is supposed to be impervious to ethanol but I haven't tried it yet.

[PeWe]

I have a box home waiting to be used.
RESTOM TANK SEALER & REPAIR SUPERKIT 15-25 LITER
http://www.matthys.net/english/ezshop/ezfind/EN_article_detail.asp?EzShopCode=2222000002143015122&EzShopAccount=&Article=R+SUPERKIT+15-25&EzShopStartPosition=0&EzShopTarget=3&EzShopCategory=0&EzShopType=0&EzShopScope=10&MasterCat=171

I ordered this from a Swedish site  www.restom.se
I'm convinced that it will be fine. I'll be back with photos when ready... next year before spring :-)

[bwaller]

I've never tried Caswell, but I've had many treated with redkote, but if there are any holes the rad shop will solder the tank first. The tank on my racebike was lined with Redkote, (4 yrs.) and I used mixes of race gas but always drained the tank after a race weekend. I never saw the gas turn red, it surprises me that ekpent has had that happen, doesn't sound good.

[ekpent]

  I will try and post up a couple pics of the color change I have noticed with it after about 3 years. Think I have done around 4 or 5 tanks with the Red-kote. Still have a couple full quarts of it around. I will use it again if needed, it is very easy to use and the price point is good. This is the Guy that I have bought all mine from, he has been selling it for a long time, Price has gone up a little but nobody around town could touch his price ($24.95 now) and fast and FREE shipping. You can get at least 2 tanks out of a quart with some left over. http://www.ebay.com/itm/RED-KOTE-GAS-FUEL-TANK-SEALER-LINER-REDKOTE-QT-/281194721916?hash=item417882f27c&vxp=mtr#ht_432wt_992

[HondanutRider]

POR-15....check it out instead.  More highly recommended than any other.  I've had good experiences with it in plugging pin-holes and lining tanks as have others, and it seems impervious to ethanol.

[MoMo]

I've never tried Caswell, but I've had many treated with redkote, but if there are any holes the rad shop will solder the tank first. The tank on my racebike was lined with Redkote, (4 yrs.) and I used mixes of race gas but always drained the tank after a race weekend. I never saw the gas turn red, it surprises me that ekpent has had that happen, doesn't sound good.

That was my experience with Redkote---the gas turned red and the carbs subsequently clogged...Larry

[Geeto67]

If you are seeing red gas I am thinking it was an old batch and it settled out a little and wasn't remixed properly. I don't know what effect it will have but the red color is just a dye to help you see if you got coverage, its usefulness ends when the tank is dried). I have heard of people tinting caswell the same way when lining plastic tanks so they can see if they have coverage. I like Por15 in metal tanks because it is silver and even though it is not a natural metal silver it makes the tank look stockis when done.

The old liners regardless of make were not really setup for alcohol fuels. Old Kreem liners esp never seem to last once the new stuff hits it. I have a norton interstate tank that used to have a great kreem liner in it that lasted for years - first batch of e10 and it bought the farm.

[thrutheframe]

Did I miss something?  Are we talking about bridging holes in a gas tank with RedKote or Por15?

[Tews19]

Kawabunga,

Where are you located in WI? I have a 550F original tank that I do not use with matching side covers.

Welcome to the site and any pics of the bike currently?

[kawabunga]

Did I miss something?  Are we talking about bridging holes in a gas tank with RedKote or Por15?

It was, I decided against it.  There are two holes that are just too large.  I found another tank already and will just try to color match as close as possible.
Unfortunately, the original tank just wasn't meant to be.

[kawabunga]

Kawabunga,

Where are you located in WI? I have a 550F original tank that I do not use with matching side covers.

Welcome to the site and any pics of the bike currently?

Hudson area.  Almost Minnesota but not quite 

I've already picked up a clean tank ready for paint, but thanks for the offer.  (Unless it's the metal flake orange, then I might be interested)

Couple pics...
The day I dug it out.  How it sat for 21+ years.


After a little clean up.


Another.


Condition of tank.  Not good.  After conversing with a colleague that's been building/restoring bikes and cars for 20+ years we've decided the tank will make a nice wall piece.







Thanks for all the help, though!  Much appreciated.  Learning a lot with this build and this forum has been a tremendous help already 

[ekpent]

Those are some non typical rust out areas and they seem to be spread out over a pretty large area. The metal inside the whole tank must be getting pretty thin and a good de-rusting could open up even more areas. Think you have made a good decision. Shame the ole' girl sat so long. Did you ever hear the reason why ?