Tank for my '77 750F SuperSport

[rafanomenon]

Here is the tank I just got off ebay for $140, 3-day air

it was originally $100, but i wanted to work on my bike this weekend. I've really gotta do something about my patience and impulse shopping habit :

It looks like there is going to be a bit of work getting rid of the rust on the inside. I've been doing research for the past week as far as the best method. I bought the Kreem treatment, but have heard horrific stories of Kreem jobs gone bad. There is muriatic acid, phosphoric acid, CLR, limeaway, Rusteco, Zap, electrolysis... after consulting with a few mechanics and restorers who have tried many of these said methods, I think I'm going with the muriatic cleaning, then follow up with phosphoric acid, both available at Home Depot down the street. As soon as I rinse the phosphoric acid out, I'll give it a rinse with soap and water, then WD-40, then gas. If I'm messing the steps up, someone throw something at me!!!

*fingers crossed*

 

[Tim]

For off-the-shelf product I'd go with POR-15.

 

[rafanomenon]

For off-the-shelf product I'd go with POR-15.

isn't POR-15 just used for a tank liner/preventative? I actually think I'll be going with this method: http://dotheton.com/index.php?topic=4564.0

Seems to have worked for Rudy, and other who have tried it. Also sounds a lot simpler to slosh around liquid from one bottle than to do one step, rinse, second step, rinse, third step, rinse, then use a preventative.

 

[Tim]

The POR-15 motorcycle tank kit comes with both the cleaner and the lining material. I've used the kits a couple of times and like them.

But for sure I'd be trying some home-grown techniques first.

 

[rafanomenon]

The POR-15 motorcycle tank kit comes with both the cleaner and the lining material. I've used the kits a couple of times and like them.

But for sure I'd be trying some home-grown techniques first.

hmm.. yeah i see myself trying the kit method eventually. hell, i've now stock-piled 3 CB750F tanks! I guess there's really no immediate need for a sealant if the tank holds fuel well, and there are no pinhole leaks.

 

[rafanomenon]

I got the tank today, and it's in pretty good shape - on the outside. What the seller neglected to mention in the description was that the 'minor rust on the inside' came with one crappy Kreem job. I looked inside with a flashlight, and along with rust and other dry gunk swishing around, I could see huge chunks of the Kreem epoxy sealer peeling off like no one's business.

I called a few local cycle mechanics and retailers, and they had no answers. Typical. I then went online and found out that MEK (methyl ethyl ketone) or acetone will do the job to get the Kreem sealant off. I called Kreem directly and they confirmed this. Good to know if you mess up a Kreem job and have to start over.

I also picked up a few rust solutions: CLR, Zep rust remover, and good ol' muriatic acid. The bad thing about the latter is that it's an etcher, and may eat right through the tank of there are any slight pinhole leaks and/or rust that has penetrated deeper than the surface. Anybody have success with muriatic acid? I also heard phosphoric acid helps. If I can't get enough balls to give it a shot, I may just hook everything up electrolysis style, and remove all rust that way.

check my blog for full details: rjrcreative.com/bike

 

[rafanomenon]

Been awhile since I updated this post. Been tracking everything in my 'project post': http://dotheton.com/index.php?topic=7707.msg67696#msg67696

I got got moving on pounding dents into my tank. I had a spare one laying around that my cousin ran over (boo) that had no business being used for anything else, so I practiced on that. I started by tracing a rough template, and pounding the middle going outwards. Some parts dented different that others. I made sure to note this for when I dent the real tank. The weird parts were the front-middle of the tank, and near the bottom.

I plan on filling the dimples and imperfections with bondo, then sanding and priming for paint.

I wanted to use a hammer with a sharper end to get a more defined and accurate dent, but this caused a lot of dimpling as you can tell in the pictures. I plan on using a rubber mallet with one end sanded down to a sphere shape, or a deadblow hammer. seems like people have had a lot of success with this, so i'll give it a shot.

I've heard mixed reviews about using bondo to fill in the dimples before sanding a prime and paint. Isn't that what bondo is used for? What are the pros/cons? Anything else out there that anyone recommends?

 

[rafanomenon]

Disclaimer: This isn't pretty :-\

Got started denting on the actual tank a couple days ago. As stated, it dented unpredictably using the orange deadblow hammer. I didn't notice how imperfect it was until I stripped and sanded.

Overall, I'm happy with the general shape and location of the dents, minus the bastard crease towards the middle-bottom, especially on the right side of the tank. I didn't want to overdo it, so I stopped. I don't think this tank is totally scrap - just a little more bondo and shaping work than I had originally planned. The dent on the left side looks different in the pictures, but it's just the direction that the light is hitting the tank. The shape is pretty symmetrical on both sides.

Bondo and general shaping tomorrow and Friday. Paint this weekend!

 

[Disliked23]

Yeah, that's what bondo is for. In my other post I was just saying I used too much so the sanding was a bitch. Someone mentioned dyna-filler and that it was easier to work with, but I can't find it anywhere. If you do use the bondo, don't start sanding with anything lower than 80 grit. I accidentally grabbed some sixty while I was sanding and it proceeded to create nice little holes all over my previously flat sanded section of bondo. F@$K!