decals/graphics

[OhioTed]

This is a question about decals and graphics in general, not just as they apply to Pentons, so please bear with me.

I have had varying levels of success with application and longevity of graphics, especially on fuel tanks.  Fiberglass and plastic tanks represent the biggest challenge of course, because of their porous nature.  Currently, I am struggling with graphics on a plastic tank.  

First I simply installed a set a graphics, which I purchased from Reproduction Decals.  I've applied their product to metal tanks in the past with excellent results.  However, in the case of the plastic tank the graphics bubbled up and were destroyed within a couple of weeks.  I then started over by applying Caswells epoxy sealer, which I found out about on the POG site.  The product had worked perfectly for me in previous application to a fiberglass tank.  I then installed another new set of graphics from R.D. and was happy as a clam for about two months, when the decals began to bubble again.  

This bike sits, a lot, so I had not looked inside the tank since first filling it after completing the installation of the sealer.  To my surprise, there was a big split right down the "backbone" of the tank and the sealer had popped loose from the inner surface.  I had followed Caswells prep instructions to the letter - same as I had for the fiberglass tank, but apparently something didn't work out right.  

Not sure what more could be done, I thought that given the bike's limited use I would keep the tank drained and only fuel it when in use, hoping this would keep the graphics in place.  So, I drained the tank, prepped the surface, and installed yet another set of graphics from R.D.  It didn't work.  The decals began bubbling almost immediately and the next time the bike was fueled, they were ruined.  

So, I figured that the tank's plastic is either saturated with fuel vapors, or just so porous that nothing will hold up on its surface.  It would appear that graphics are simply not practical.  BUT - I rode this bike at the ISDT RR, where I installed an AHRMA sticker right on the top of the tank.  And guess what?  The RR was nearly a month ago and that AHRMA sticker is still flat and smooth.  Not a single bubble in it.  

So what's the deal?  How can one graphic bubble like crazy while another does not?  If fuel vapors migrating through the plastic causes this situation, why has the AHRMA sticker not been affected?  Also, when I first got this bike (some) of the original graphics were still present on the tank and they were not bubbled.  I would welcome any comments or help on this subject.  Depending on how a bike is used, graphics may or may not hold much importance, but I'm pretty anal about appearance so I want the bike to look good.

Note, Meteor Mike told me that he uses a different brand of graphics, which are perforated.  I've checked them out on bikes they have been applied to, and have seen them advertised on Vintage Iron's website.  If they do work, that would be one potential solution, but I must admit that they do compromise the "oem" appearance I am seeking.  Suggestions?  Comments?  Advice?  Thanks.

                                             Ted G.        

[t20sl]

My guess would be the adhesive base type.  Latex, petroleum, acrylic, silicone etc???
Ted A.

[Britt Boyette]

The crosslink plastic used on gas tanks since day one have always had that problem. The don't take well to sealers either and can actually crack if you paint them depending on thickness of paint. The decals that do the best seem to be plastic backed graphics that are perforated. There does seem to be some differences in adhesives used by some decal companies but I don't know what they are. They will bubble at some point. My game plan is to not leave gas in the tank. I always drain it out and on fiberglass tanks, I don't use pump gas unless it comes from a marina because there's no alcohol in boat gas. Some boats have fiberglass (GRP) tanks and regular modern pump gas can soften the GRP resin bonding. Race gas is another avenue that works well. Using these methods, these tank decals have been on my RM370's plastic tank for about five years now. They are starting to look a little ratty now but it's not a beauty queen.



Britt Boyette
1976 125 MC5

[Gordon Brennan]

I restored a Yamaha TY350 a few years ago and got my graphics from overseas. They are very thick and looked great. The company actually makes special graphics, just for gas tanks. I bought the standard graphics, since the bike is a rider and falling during trials is typical. (Or maybe I just fall a lot). Anyhow, I always emptied the tank, even after a short yard practice. The entire time, since putting them on, I never had a single bubble  or wrinkle. I began another trials bike project and only rode the TY a little here and there. ONE time, I put it away, in the garage without emptying the tank. A few days later, I walked by and couldn't believe it. The tank graphics were a mess. All wrinkled and bubbled. Just that one time of not emptying the tank did it.
I think the only way you can avoid the situation you have described is to buy only the best high quality graphics and empty your tank every time your done riding.
I'd like to add that there's nothing wrong with Reproduction Decals. I have used them as well on metal tanks, with no problems.

[DKWRACER]

If there was a "magic pill" to take to solve the problem.I would buy one at an instance. I don't have that pill. What we do have are 30 yrs old gas tanks that have been subjected to numerous fuel/oil combinations...You should see how many times I have painted tanks, only to see a blister...........But, in spirit we should try!
I have 18 Pentons, all deserving of the things that that we want. Some are original, some have been painted. I tackled this problem from the outside.......Up untill this post, I have been very lucky with POR 15 as an exterior coating ( 5 coats) combined with epoxy primer...is this the answer?.........drain the tank, live the dream, and remember, we would be "nowhere" without a Penton

respectfully<

Tom Brosius

[454MRW]

Tom,
I am also now coating tanks on the inside with POR-15 Clear with good results as long as the tank is properly cleaned first to remove the maximum amount of oil that previously penetrated the fiberglass. (Rinsing with laquer thinner followed by MEK or Acetone prior to coating). Coating the inside AND exterior also I believe would virtually elimanate the "breathing" effect of the gasahol's effect on the tank and preserve the decals in the process. Only time will tell for sure. Mike

Michael R. Winter
I enjoy rebuilding and appreciating Pentons!
1974 250 HS Pentons-1980 KTM 175-400'S

[Doug Bridges]

One thing that is in almost all pump gas any more that cant be good for either plastic or fiberglass or who knows what on a vintage bike is the alcohol and other chemical additives that are unknown to most of us. I have been useing aviation fuel purchased at our local airport. 100 octane, gaurenteed no alcohol and has a small amount of lead in it. this is a lot like premium fuel use to be in the early 70's. I have left it in a nicely painted fiberglass tank for a couple of months and have been keeping a close eye on it. The fiberglass is still very hard on the inside and I have seen no signs of any deterioration of the fiberglass, paint or decals. On the other hand, I put pump fuel (with alcohol) in another Penton I had and within several days the fiberglass on the inside of the tank was getting soft to the touch and a little like jelly. I drained the gas as soon as I saw this and after a few days it was hard again. I think that it can only be benificial for any of these old bikes to seek fuel without alcohol and other unkown additives. I think that aviation fuel is very consistant across the country and might be worth giveing a try.

Doug Bridges
73 Jackpiner

[Britt Boyette]

I now have a race tank which is plastic, and a show tank that is the original fiberglass tank. The show tank will most likely never see fuel again.

Britt Boyette
1976 125 MC5

[OhioTed]

Thank you for excellent, informed response, gentlemen.  It would seem there is no "easy fix" to this situation.  At least now I do not feel like a dummy, for having overlooked something obvious in my efforts to apply and maintain graphics.

There is another option I had considered and would appreciate your input.  My plan would be to install a very thin, hard plastic sheeting to the location on the tank where the graphics are applied.  Cut to shape and afixed with a malable adhesive, I thought this method may provide a fairly unobstrusive means of mounting the graphics yet provide a "barrier" from fuel vapors.  Opinions?

[Britt Boyette]

If you could make it look good then it may be a good plan, I'm considering making a fiberglass skin/cover for my plastic MC5 tank that I could paint and decal over without worry.

Britt Boyette
1976 125 MC5

[OhioTed]

That certainly takes my idea a step farther, Britt.  I see that the DC Plastics people are offering plastic fuel tank skins for select models.  I did not look to see if they have anything for Pentons, though.

[OhioTed]

DC Plastics update:  So far, DCP has a tank skin only for an '81 KTM (see link) http://www.dcvmx.com/xcart/product.php?productid=17991&cat=325&page=2  However, they are introducing new parts all the time, and with some input from us maybe we can get them to produce a "skin" for CMF mx & enduro tanks.  Send them your comments and encouragement: http://www.dcvmx.com/xcart/home.php?cat=455

Be sure to use the link provided.  I typed in dcplastics.com and got the website of a company which makes breast implants!  Yoi!

[OhioTed]

I was hoping to get some additional information from Mike Winter, but have not heard from him.  Are you out there, Mike?

[OhioTed]

I was hoping to get some additional information from Mike Winter, but have not heard from him.  Are you out there, Mike?

[454MRW]

See my response on the topic "Calling Mike Winter"

Michael R. Winter
I enjoy rebuilding and appreciating Pentons!
1974 250 HS Pentons-1980 KTM 175-400'S