Problem with decals on gas tank..

[patblkwell]

A few weeks ago, I put some honda decals on my aftermarket plastic gas tank and within the first week, the decals started to bubble up. I cleaned the tank thoroughly to remove any dirt/oil before I installed the decalse but it didn't help for some reason. Someone told me that the plastic tanks have some kind of chemical reaction with the decals....anyone had an experience like this?? Is there any kind of solvent that can be used to remove any oil and prep the tank before applying decals? I was thinking about lightly sanding down the area of the tank where the decals would go....let me know what yall think-thanks

[CHAINSAW]

Plastic tanks breathe. You will have to Kreem the tank to keep decals or paint on plastic tanks.

[patblkwell]

What exactly do you mean by Kreem?

[ClayW]

Kreem is a tank sealant kit thats on the market. Most bike shops have it. In my book its crap. I did my big red with it and followed the instructions by the T and its still coming loose inside the tank. The stickers will not stay on that plastic tank. My XR500R's are bubbleing like crazy. I just rub them down periodically. They stay on that way.

ClayW

[patblkwell]

Oh ok, yeah I took a needle and popped a most of the little bubbles that showed up. I rubbed them down a few times and the stickers stay on but every now and then a few small bubbles will pop up. I might try sanding the tank lightly, then putting the stickers on.....who knows???

[CHAINSAW]

I might try sanding the tank lightly, then putting the stickers on.....who knows???
I do, and it wont work. That is the same reason why dirt bike graphics have holes in them. There is no way to keep stickers on a plastic gas tank, unless you
A) have big holes for the tank to breathe in the stickers
B) Kreem your tank

[PowerTrike]

Cutting small slits with an X-acto knife in larger stickers or decals will help some.

[GreenLightening]

The problem is with the mold release agents they use when the make the plastic tanks. I have always had problems with stickers on my Tecates tank.

I may have an answer for all of you.

I dont know if it will work on a stock plastic tank with no paint. Before I paint any plastic, whether its a front/rear fascia on a honda or ford or plastic fenders on an atv. I have always used a plastic prep. I use dupont, I could get you the part number. It smells like hell, but it really works. It cleans mold release agents from the plastic, oil and also reduces static electricity, before the painting process.

Anyway I painted the tank on my tecate 4 months ago, put some dirtbike kawasaki stickers on over the paint, and have not had a single bubble in the paint or the stickers.

Just my 2 cents. I dont know if it will work on a bare plastic tank, It should but I always rub it in with a red scotch brite, and that scuffs the finish.

[patblkwell]

Hey Greenlightening, let me know the part # of that dupont stuff...I'm willing to give it a try. My tank is made of red plastic....do you think that stuff works if it is already painted or from the factory like that?? Let me know what you think..thanks.

[atctim]

From what I understand, the reaction is not from a release agent from making the plastic tank from the mold, but rather the gasoline evaporationg from within the tank. You see, plastic is much much more pourous than metal. When the gasoline inside evaporates, the majority of it goes out through the breather on the tank cap, however, the outside layer of gas (the thin layer touching the tanks inside walls evaporates and can't just go out the cap, so it "seeps" through the tiny holes in the plastic, out of the pourosity. Keep in mind the holes are not big enough for gas to leak from, but in the evaporation process we are talking about molecule size particles. When they come out through the plastic, it bubbles up stickers. As someone already mentioned, that is why newer motocross bikes have hundreds of slits cut into the decal graphics. I believe that the "Kreem" would works, because it would make it air tight, and is more dense (less pourous) than the plastic, thus forcing all of the evaporated gas to go through the breather hole, but I also think that Kreem is designed for metal tanks, not plastic so maybe it won't bond like it does to metal. If you note, no one has problems with fender decals, because there is no gasoline in the fenders. And fenders would have the same release agent as tanks have.

[CHAINSAW]

yeah, it says right in the Kreem instructions, "Do not apply to plastic tanks" It does work, I have done it, and never had a problem with it. If you clean the tank properly, it will work.

[350x'inNY]

I was wondering if you had a new, never used tank, if you could

A.) Paint the sticker application area with a "clear coat" plastic fusion paint. or...

B.) Do A, and also spray the back side of your sticker with clear coat paint and apply it. I think the wet paint might "soak" into the plastic and also bond the sticker to the tank once it dried.

What you all think? I got "HONDA 250" stickers to put on that IMS tank on my 82R!

Bruce

[GreenLightening]

I will get you the # of the product. Like I said already, I dont know if it will work or not. Its worth a try. you can use it on already painted plastic, Its made to and works best on bare plastic. I have put a lot of thought into this problem before I painted my tank, and I could not find anyone with a sure answer to why tanks do this. I just dont buy into the fact that the fuel could be evaporating through the plastic. Why is there never any fuel residue on the tank? how could the plastic possibly hold up for 10 or 20 years with fuel evaporating through it and drying it out all the time? why will a tank with no fuel in it still bubble the stickers? Why would the fuel evaprorate through tiny holes in the plastic when fuel evaporates through the top and there is a wide open breather hole in the top.


If you note, no one has problems with fender decals, because there is no gasoline in the fenders. And fenders would have the same release agent as tanks have.

thats another question I have, are they really the same plastic? I dont think so. If so why would the old tecate fuel tanks fade to almost white after 20 years and the fenders will stay green? I dont think they are the same type of plastic.

As I already said, I am by no means an expert on this, and I am not claiming to know exactly what happens with this problem. I just have some questions that I dont know who can answer.

[patblkwell]

I have never heard that the fuel can seep through the gas tank. The reason that the stickers on plastic fuel tanks don't adhear very well is because the tanks are made of a different type of plastic that the fenders and they have some sort of oily coating on them to keep them looking shiny. We need to figure out how to remove this oily coating on the areas where the decals would go....The plastic on the tanks is thicker and softer than that of the fenders in my opinion.

[Dynofox]

I had the same problem with the tank decals on my aftermarket 350x tank. I just pulled the decals off the tank and put them on the scoops, thought they looked better there anyway.

[triz25o]

I had the same problem with my bw200 all I did was take the tank off let all the gas evaporate out and put the stickers on when the tank was empty and bone dry and they have lasted perfectly for the last 5 years

[patblkwell]

How long did you leave the stickers on the tank before adding gas to it again?

[GreenLightening]

Here is the name and number of the the plastic product that I use. I havent used it for just the application of stickers, it may or may not work. The salesman at the paint shop where you buy it may have a better idea.

Dupont

Plastic Prep

2319s

[triz25o]

I waited about a day or two

[TrikerR]

I will get you the # of the product. Like I said already, I dont know if it will work or not. Its worth a try. you can use it on already painted plastic, Its made to and works best on bare plastic. I have put a lot of thought into this problem before I painted my tank, and I could not find anyone with a sure answer to why tanks do this. I just dont buy into the fact that the fuel could be evaporating through the plastic. Why is there never any fuel residue on the tank? how could the plastic possibly hold up for 10 or 20 years with fuel evaporating through it and drying it out all the time? why will a tank with no fuel in it still bubble the stickers? Why would the fuel evaprorate through tiny holes in the plastic when fuel evaporates through the top and there is a wide open breather hole in the top.



thats another question I have, are they really the same plastic? I dont think so. If so why would the old tecate fuel tanks fade to almost white after 20 years and the fenders will stay green? I dont think they are the same type of plastic.

As I already said, I am by no means an expert on this, and I am not claiming to know exactly what happens with this problem. I just have some questions that I dont know who can answer.

im sorry, but your wrong. plastics fuel tanks do allow fuel "vapours" to seep through. and the reason that stickers will still bubble when there is no fule in there because there is fuel trapped in the tank and in the plastic. say if you get a brand new bike, never had fuel in the tank, the stickers will not bubble. the tank can hold up for years because the fuel dosent corrode the plastic...even if its in the actual plastic. and its not the fuel going though the tank...its minimal amounts gas fumes, thats why theres no "visible" reside left, but theres usually a tiny amount siting on the surface, so small amount that its not noticable. and the reason that stuff to paint plastics tanks works is because it blocks the pores of the tank.

well thats just my say, have a nice day