Topic: Flaking paint on top of the gas tank?

[kyle750]

It must have had some damage on the top of the tank that was fixed in the past.

I believe you are absolutely correct.  Cleaning up the top now.

[kyle750]

Sanded lightly with 120 grit and quick coat of WD-40 to prevent flash rusting to the exposed metal

[kyle750]

BTW  new handlebar bolts and new steering stem bolt.  Totally backwards I do things   

[Mark1976]

   Deep six it, that tank if repaired will likely do the same thing all over again, it looks as though it was definitely repaired at some point (the entire top is filler and the neck and latch excessively brazed) and the top of the tank "oil cans" (flexes) thus all the lifting and cracking of the filler on top. It can be refilled and finished if you'd prefer but your throwing away good money just to see it happen all over again. And the last thing ya want to put on it is wd40, it just contaminates the surface and makes adhesion of filler and then paint impossible. Your tank, your time, your bike...

[kyle750]

   Deep six it, that tank if repaired will likely do the same thing all over again, it looks as though it was definitely repaired at some point (the entire top is filler and the neck and latch excessively brazed) and the top of the tank "oil cans" (flexes) thus all the lifting and cracking of the filler on top. It can be refilled and finished if you'd prefer but your throwing away good money just to see it happen all over again. And the last thing ya want to put on it is wd40, it just contaminates the surface and makes adhesion of filler and then paint impossible. Your tank, your time, your bike...

Thank You for your evaluation.  The brazed area around the neck and latch looks really bad!

[jonda500]

Body filler directly onto clean bare metal only (no holes) is how it always was professionally done last century, And is also how I did my 400-4 tank back then - it still hadn't "oil canned" or cracked at all 5 years later when I sold the bike.
John

[kyle750]

I was fully expecting to see extensive and thick rust under the paint and I was shocked to see how clean the metal actually was.   Only very minor surface rust where the cracks formed.  Nearly the entire surface under the paint was completely rust free.  The minor surface rust sanded out in minutes leaving only slight trace darkening to the metal.  My biggest concern is that there are tiny holes around the neck or latch and escaping gas vapors caused the paint cracks.

I really don't know how to evaluate this tank? 

[bryanj]

With that amount of repair around the neck its junk

[newday777]

Contact Yamiya to get on the next batch of tank and sidecovers. A friend here in NH just got a set from them in the gold for his K2 and it is fantastic.

https://www.yamiya750.com/index.php?main_page=product_info&cPath=246_157_271_242&products_id=2651

[kyle750]

Contact Yamiya to get on the next batch of tank and sidecovers. A friend here in NH just got a set from them in the gold for his K2 and it is fantastic.

https://www.yamiya750.com/index.php?main_page=product_info&cPath=246_157_271_242&products_id=2651

A very strange coincidence as I was looking at the Yamiya gold just as you posted the comment 

[kyle750]

Tank is a goner and now moving forward.  Better to learn this now.  Thank You Gentlemen!  I may have dead shocks and a crappy tank but I love my steering stem bolt 

[Ozzybud]

Body filler directly onto clean bare metal only (no holes) is how it always was professionally done last century, And is also how I did my 400-4 tank back then - it still hadn't "oil canned" or cracked at all 5 years later when I sold the bike.
John

Your bike was probably not left out in the elements. This is exactly what happens when you put filler directly on metal.  .This is why we don't do it anymore if you want it to last indefinitely. 5 years is not a lot of time. Filler provides zero protection as a moisture barrier.

This is Googles first answer

Yes, applying body filler directly over bare metal is generally not recommended and can lead to problems like poor adhesion, cracking, and eventual rust. It's best to apply an epoxy primer first for proper adhesion and rust protection.

[kyle750]

At this point I will most likely wait for the next batch of candy gold tanks from Yamiya but just for kicks I found this used tank on ebay and curious to hear  other members opinions of this tank.  Most of the used tanks I see on ebay are really bad junk and buying used is always a big risk. There are many paint shops in Thailand that do good work so it would be a very reasonable cost to repaint. Thanks!

https://www.ebay.com/itm/226585881431

Where are the holes for the HONDA badges on the sides?

[bryanj]

They have been filled in then the whole tank repainted, if you want original wait for Yamiya as that would cost a lot to dig out filler and repaint plus you dont know what damage is under that paint

[kyle750]

But the inside of the tank looks clean and I can't see any rust anywhere.  Not sure where the tank has spent most of its life but the seller is located near Riverside CA (semi arid mostly dry desert). 

[Mark1976]

   Used tanks are a big gamble at best, especially if you have no idea who your dealing with, and it's ebay, and at that price point that's just way to much. Be patient, a better alternative exists. You'd be surprised...

[kyle750]

   Used tanks are a big gamble at best, especially if you have no idea who your dealing with, and it's ebay, and at that price point that's just way to much. Be patient, a better alternative exists. You'd be surprised...

Agreed.  Patience is always best.   I am sure an original  NOS candy gold gas tank from 1972 still in the Honda box is right around the corner 

[Phoenix]

I leaned my bike over to address the dynamo.  I had it tipped for a day.    Turns out there was a slight leak from the seal om my cap.  The paint flaked off with about a 1" ring around the inlet.  Not much you can do about it.  I replaced the seal.  Might be a good idea to replace the seal if you like your paint.

[BenelliSEI]

If that tank is clean inside, I’d clean off the braze and repair that neck properly.

[Ozzybud]

I could repair your original tank no problem. Talk to a bodyman  in your area.

[M 750K6]

If that tank is clean inside, I’d clean off the braze and repair that neck properly.

Agree. Also, that dent should push out with an inner-tube inflated inside the tank. Looks like there's filler under the remaining paint, so the whole thing needs to go back to bare metal.

First, empty the petrol into your lawnmower. If the inside is good, then strip and sort the dent and filler cap and off to a good painter. If there's rust inside, Evaporust on the inside would be my choice.

Wasteful to just sling the tank IMHO.

[kyle750]

I have no experience restoring old bikes so the guidance and different opinions on how best to proceed are very much appreciated.  Thank You!

When I first bought the bike I was extremely concerned with the flaking paint on the gas tank.  It really bothered me not knowing what to do.
 It looks terrible and I did not understand what the problem is?  I still don't fully understand what the problem is.  But removing the paint and seeing undeneath I can better see what has already been done.  Perhaps it can be fixed properly and never be a problem again but there is always a chance that it will never be corrected perfectly and the paint cracks again.  I don't want to go through all the effort and have to "worry" about it.  There is enough in life to "worry" about.

I will be looking for a replacement tank and sent an email to Yamiya. I am still open to buying a solid, dependable, and worry free used tank and then repainting Gold.   Thank You!