Cleaning the yellow stained end caps

[Silverwanabe]

Why do the endcaps turn yellow anyway?
Are they vacuum formed ABS?

Both are mine are fiberglass.

ps, the 70's baths with the flower print are so retro.....

[Splitrock]

The one I had out was plastic, not fiberglass. Both are yellowed like a camel's tooth.

[ND10CentCan]

Originally Posted by Silverwanabe

Why do the endcaps turn yellow anyway?
Are they vacuum formed ABS?

Both are mine are fiberglass.

ps, the 70's baths with the flower print are so retro.....

I actually did save some of the flower print stuff that came out of the bathroom. I didn't realize there was a pull down blind until we took the end cap out of the bathroom and there it was. I have it saved away for posterity. I can see it now...."What in the world is this?" after we are long gone. Maybe they can donate all of it to a museum?

[vswingfield]

Originally Posted by Silverwanabe

Why do the endcaps turn yellow anyway?
Are they vacuum formed ABS?

Both are mine are fiberglass.

ps, the 70's baths with the flower print are so retro.....

67s-fiberglass endcaps. Newer-ABS.

Plenty of advantages for ABS over fiberglass. Not only do they turn yellow, but they crack too.

OK, enough sarcasm. I do wish the endcaps in my 83 Excella were 'glass like in the 67 Trade Wind.

Sometimes I fantasize about pulling the caps, making a mold from them, and making a pair of fiberglass replacements minus the cracks. Maybe next lifetime.

[dwightdi]

Vacuum formed ABS endcaps. ABS stands for Acrylic, Butadiene(rubber) Styrene, mixed plastic compound. The Butadiene rubber degrades due to age and UV exposure and turns yellow and loses some of its rubber properties. That is why the endcaps yellow and become brittle. You can not restore the ductility, but you can bleach the yellow out. Any current cracks can be stopped from propagating further by drilling a hole at the end of the crack. Coating the whole thing ( in place) with a thin layer of fiberglass and paint is an alternative.

[Roadrunner]

We had the same problem on our "78" Ambassador. Decided to scrub with 409, hit it with some sandpaper, and use Krylon plastic paint. Looks great and holds up well.

[Aage]

Originally Posted by vswingfield

Sometimes I fantasize about pulling the caps, making a mold from them, and making a pair of fiberglass replacements minus the cracks. Maybe next lifetime.

Could be an interesting business, Vaughn. Of course, as I wrote that, it occurred to me that there are probably a dozen or more styles and shapes of those end-caps. :/

[fwsieft]

We have a 1975 27' airstream. Could someone tell us how to fix cracks in the end caps they are really MAJOR.

[Aage]

Originally Posted by fwsieft

We have a 1975 27' airstream. Could someone tell us how to fix cracks in the end caps they are really MAJOR.

Well, I just tried the Google version of the Airforums.com Search option, one of the links in the top blue horizontal bar and got this list.

Have a read through there, might help...

[UserKirk]

Do NOT use the clearcoat from Krylon Fusion paint after painting. I painted my endcaps using Krylon Fusion dover white gloss paint. I waited 7 hot days and then applied the Krylon clearcoat. Disaster followed - in spots, my white paint faded to light yellow. I wet sanded one of the spots and found that the clearcoat had yellowed the top coat of white paint. The under coats were still nice and white. I found on other sites where kids had painted their motorcylce helmets and four-wheelers white only to wreck their creations with the clearcoat. After reading the msds, clear coat is just solvents. I had preped correctly and wet sanded everything before starting. Story short- do not use the clearcoat.

[lisapye]

Hi Splitrock, I like your train of thought, but what did you figure out to be step 2? Did you replace them or figure out another fix? Thanks so much... Lisa

[Splitrock]

Originally Posted by lisapye

Hi Splitrock, I like your train of thought, but what did you figure out to be step 2? Did you replace them or figure out another fix? Thanks so much... Lisa

Hi Lisa,

If you followed my blog you saw I had the rear end cap out to heat and roll out an exterior skin dent. The rear cap didn't have any cracks, just yellowed, so I put it back in with no problems. I expect at a later date I'll mask it off and paint it.

The front cap has that molded storage cabinet with the tambour doors. It's stress cracked but it's fine and functional. To paint that one I'd have to remove it, fiberglass the back side, fill the cracks, and reinstall it. I may do that. I had thought of just applying headliner material on the front cap.

My plan was to do all the repairs and maintenance, seal the exterior seams, install a new air conditioner, new power roof vents, replace all the appliances, replace the plumbing, and install new fixtures before I installed new floor covering and built new wall panels for the center bath.

Now I'm building cabinets, new closets, new countertops, and installing new furniture. Next season I'll strip the exterior, replace the awning, and add rock guards. Dealing with both caps will come later in my project. Maybe not even next year.

My goal was to have the trailer ready to take a little trip this fall but my wife says she's not interested in being associated with the trailer until it's stripped and buffed. That buys her another year and lets me use the trip money for more shop tools. :-)

Gary

[jweathe1974]

I'm replying to an old post, but because I've found a way to clean and brighten my old yellowish ABS plastic AND it works!!!
Peroxide Method (for ABS plastic)

You Will Need:

• Hydrogen peroxide
• Oxy laundry booster
• Sunshine or UV light
• Water
• Bucket or large bowl
• Rubber gloves
• Goggles

Steps to Whiten the Plastic:

1. Begin by protecting yourself with rubber gloves and goggles.
2. Fill the bucket with hydrogen peroxide.
3. Add ¼ teaspoon of Oxy laundry booster for each gallon of peroxide.
4. Place the yellowed plastic pieces into the solution and allow them to soak.
5. The soaking time will vary with most pieces whitening in 2-6 hours. The mixture will last for up to four days before it needs to be replaced. Retr0Bright has also developed a way to make this into a gel that can be spread onto the plastic. This is especially helpful for larger items.
6. Set the items under a UV light or out in the sunshine.
7. When the item has reached the desired whiteness, remove and rinse thoroughly to remove any remaining cleaning products.
8. If necessary, wash with dish detergent and water.

[dwightdi]

The common yellowing of the ABS plastic endcaps can have several different causes. The remedies can be quite different.

The poster above is addressing the discoloration that has been caused by the degradation and yellowing of the "B" rubber component of the ABS plastic. The bleaching described should be effective in restoring the color. It, however, does not restore the ductility to the plastic and may reduce it slightly. When the plastic becomes brittle with age, cracking, due to flexing, as the trailer goes down the road, will result. You need to stop the cracks from propagating by drilling a small hole at the end of the crack.

If the stains are caused by permeation of tobacco fumes, a very though cleaning with very strong detergents, which can permeate into the plastic, is a better choice.