[LearMech]

Hey guys,



One of the 2-3 times I got to ride this year my brand new paint job began to bubble around the fuel filler area.



I assume this has something to due with the gas/fumes and needing a sealer or something. Cand somebody give me some advice on how to prevent this from happening again.



The problem has not extended too far so I can fix it without a complete repaint if I address it now.

 

[marshallf3]

TAS has the seal ring that goes in the gas cap, however by nature the cap vents a few fumes.

I liked the way some of my dirt bikes had a tube from the top of the cap.



What kind of paint did you use? Most isn't very forgiving when in contact with gasoline.



Simply not filling the tank fully often helps as well because if you use the sidestand with a full tank a bit may seep out.

 

[msleboda]

This is from another honda forum where I am a member (never did it myself):



o.k. listen carefully coming from someone who has sold approx 20 oem repainted body sets. i include this instruction with all the sets i sell because everysingle one will lift if you do not do this. i will give these instructions to you and everyone that tanks repainted. when you get the painted tank back from the painter, you will have to put a coat of clear fingernail polish on the filler neck where the paint meets the metal. after you put the finger nail polish on, fill the tank with gas after the nail polish has dried(approx 1 minute). and drive bike. after approx 3-5 days, open cap. you will see the paint starting to bubble off where the seal sits, scrap off soft/bubbled paint with a screwdriver or knife, reapply another coat of fingernail polish where metal meets the paint. same thing, drive or leave cap closed for another 3-5 days, open cap back up, and repeat process if required. usually after the 2nd application of nail polish there will be no more bubbling, but i have seen up to three times. after that, will never do it again.... if you do not do this, the gas will eventually get under all the paint and you will have a visible bubble minimum 4 -5 inches all around the gas cap.

 

[DaveF]

It seems like no matter how careful I try to be, I often spill some gas on the tank when refilling. Thankfully the paint is able to withstand this abuse.



Is it possible to apply a clearcoat to your paint that can withstand gasoline?

 

[Shep]

It seems like no matter how careful I try to be, I often spill some gas on the tank when refilling. Thankfully the paint is able to withstand this abuse.



Is it possible to apply a clearcoat to your paint that can withstand gasoline?

I'm Paint Sprayer by trade Dave.I have a lot of knowledge of paints and their capabilities.



Most pro tank jobs were done in two pack poly paints which themselves are quite fuel resistant but then they are usually over-sprayed with a Two pack Polyurethane clear coat either within the curing life of the base coat or the base coat flattened with some 600+ wet and dry and then the clear coat applied.



These days due to health and safety many paint job base coats are now,"Water Based" paints but they are sill coated with a Twin pack poly clear coat to be fuel and knock resistant but under proper extraction conditions and the using the correct respirator masks.



For the home user there are options.



You can use and old oil based synthetic clear coat such as Rustoleum Brand after flatting the tank.



http://cgi.ebay.com/Rust-Oleum-1906...8?pt=Paint_Paint_Supplies&hash=item1e5d748222



http://shop.ebay.com/?_from=R40&_tr...nkw=rustoleum+clear&_sacat=See-All-Categories



It takes quite a while to cure e.g a good week I would say depending on the ambient temps of where the tank is left and should then be sealed with a sealer wax,not a polish.In my work we usually have heater rooms with the temps raised to around 40 Deg C to speed up the curing times.Also you cannot lay it on like Normal Rattle cans.You have to,"Mist Coat" it on and let it settle and flow.



Most car acrylic rattle can paint is not durable or fuel resistant.People mistakenly think painting/Spraying is easy but it is a process and many factors have to be taken into account especially when dealing with fuel tanks.

 

[Blindstitch]

You guys are just doing it wrong. It's not that you spill but what you spill on. Yes I admit it I have a problem. I spill gas. That was actually the purpose of the bib I made for the bike. It was raised at the sided and had a hole in the center. If I spill it usually runs on the bib down to the seat area.



This area is often a problem to a lot of people. Prep is key or should I say prep overkill. If it's not deep then there was probably some sort of contamination between layers of paint.

 

[marshallf3]

I'm going with 2K Urethane DuPont Nason, same stuff they use on cars. It's relatively fuel resistant so long as you don't get stupid and try to wipe off any gas spills should they happen, you just let the gas evaporate then clean it later. The newer Ethanol based gasoline may present even more of a problem, haven't looked into that yet but it'll never be in my bike unless I'm stuck without a 100% station in reach.



The application of a good wax is also a good idea but be sure your paint has cured sufficiently before you even think of applying any. Find something with true Carnauba wax as the base, it may take a lot more buffing but it's real wax as opposed to the commonly silicone based stuff most are made of nowadays.

 

[Blindstitch]

If I remember right Kingston had problems with Spraymax 2k clearcoat. But I cant remember the exact problem.

 

[marshallf3]

Yea, but that's a totally different deal than using stuff in totally sealed cans from an automotive paint shop. The Spraymax sounds correct in theory but I can't see it working as well as the pro stuff, properly reduced, catalyzed and sprayed with a paint gun with proper timing and in 5 or 6 coats. Must be something different about it because I don't see many cars going down the road with paint eaten up by the gasoline everyone ends up spilling on occasion regardless of how careful you are with the pump nozzle.

 

[Blindstitch]

A decent amount of cars use single stage paints too.

 

[marshallf3]

Would love to be able to blame it on E10 gasoline but that's another war.

 

[LearMech]

I used the Nasson brand from an auto body supply place. it was a base/clear job. The tank cured for the entire winter before getting any fuel put into the tank but still bubbled.



The idea about sealing around the neck with a clear polish sounds like it may be the issue. We actually have some purpose built stuff made by 3M that is just like that. We use it to transition from painted to polished areas on the aircraft to seal and keep wind from eroding the paint. I think that may work for the fuel filler area as well.

 

[marshallf3]

Good, bud saddening info to know. Might also be a good idea to use a sanding block and some 400 to make sure the filler neck is totally flat.

 

[LearMech]

New development...I took the tank down to the basement today to start messing with the paint and found that the primer was still good, paint has separated from the primer. What does that indicate? or is it still possible that the fuel fumes or whatever just went between the primer and the paint?

 

[marshallf3]

Sounds to me as if your primer and paint weren't compatible. Most any true automotive paint store will know what will work with what, for instance you never put paint directly over an etch primer, you have to follow the etch primer up with a compatible primer/sealer (not just plain primer) or problems like this can occur.



Some primers also need to be wet sanded with 400 and perfectly dry before you put on any paint as some can dry with a finish that doesn't perfectly adhere to paint, or they've got a time window that needs to be followed before paint is applied.



As much work as I'm going to be going through painting mine I made darn sure to get a couple of opinions before I even started buying stuff.

 

[Shep]

Sounds to me as if your primer and paint weren't compatible. Most any true automotive paint store will know what will work with what, for instance you never put paint directly over an etch primer, you have to follow the etch primer up with a compatible primer/sealer (not just plain primer) or problems like this can occur.



Some primers also need to be wet sanded with 400 and perfectly dry before you put on any paint as some can dry with a finish that doesn't perfectly adhere to paint, or they've got a time window that needs to be followed before paint is applied.



As much work as I'm going to be going through painting mine I made darn sure to get a couple of opinions before I even started buying stuff.

A lot of the above is true however,





For etch primer:



You can apply Acrylics,polys,synthetics and epoxies over this Etch Primer as I've used it,



http://cgi.ebay.co.uk/1-x-HB-ETCH-P..._Body_Shop_Supplies_Paint&hash=item2a04c18c3a

 

[Shep]

A decent amount of cars use single stage paints too.

You would be hard pushed to find any automotive manufacturers in the last 30 years that have used 1K paint systems on cars or motorcycles.

 

[marshallf3]

A lot of the above is true however,



For etch primer:



You can apply Acrylics,polys,synthetics and epoxies over this Etch Primer as I've used it,



http://cgi.ebay.co.uk/1-x-HB-ETCH-P..._Body_Shop_Supplies_Paint&hash=item2a04c18c3a

Sounds good on paper but it's also a high-build primer that requires sanding. My metal is in perfect shape so I'm keeping things down to the absolute minimum amount of thin coats before color + clear is applied. I'm just going with the recommendations of our pros that supply the DuPont base and clear I'm using.

 

[Shep]

Sounds good on paper but it's also a high-build primer that requires sanding. My metal is in perfect shape so I'm keeping things down to the absolute minimum amount of thin coats before color + clear is applied. I'm just going with the recommendations of our pros that supply the DuPont base and clear I'm using.

By application it's only,"High Build" if the sprayer wishes it to be.

 

[marshallf3]

By application it's only,"High Build" if the sprayer wishes it to be.

Can't buy that stuff over here anyway and I'll be darned if I'm going to pay that amount of money to ship a can of common primer over here when I can get Duplicolor for around $5 a can. I'm using their etch primer and their primer sealer because the DuPont paint place said it has been tested as compatible with their base and clear coat so long as I use a light wipe over with the proper reducer before I spray the base. That tends to flatten (and clean) the primer a little more where it bonds better to the base color. After 3 coats of base have flashed, which usually happens long before you can clean your equipment and mix up the clear, the precision part comes in. Clear coat is tricky to deal with because if your spray is too fine it will end up grainy, if it's too heavy it will run. One single tiny run and you've got to let it harden, wet sand then start over which usually ends up being one extra coat than you planned for.



In other words I'm going to try to get this perfect the first time and if I can't it's just another $300 to get a pro to do it that I don't really have sitting around burning a hole in my pocket nor want to spend. Worst case I can see is that I'll have to go through a lot of rubbing and polishing compound to get it right but I bought good clear and they told me if I mix it properly and use good judgment all I'll need to do is a light polish on the final coat.