View Full Version : trailer tires - preventing dry rot?

Capt Crunch
04-30-2005, 02:05 PM
Does anybody know how to keep boat trailer tires from dry-rotting so fast? I just had to replace mine, they're only 5 years old and almost no wear, but they were starting to disintegrate on the sidewalls due to dry rot.

Does it help if you jack up the trailer in the winter to get the tires off the ground? (It's not paved where I store my boat, and it's kind of wet sometimes in the late winter.)

Does Armor-All help?

Would inner tubes help prevent them from going flat when the sidewalls got dry-rotted? What about that green "slime" liquid rubber that you put into tires that supposedly prevents leaks/flats?

Thanks for any tips. Buying 4 new tires every few years gets old fast. :evil:


04-30-2005, 03:16 PM
I'm not sure how it works on trailer tires, especially if they sit in the sun for very long, but in my hot rodding days, I dressed tires with brake fluid... this was before they even made a dedicated tire dressing.... and I'm not even sure if Armorall was around, then. If it was, I didn't know about it.

I can tell you, when you finish wiping a set of old tires with a rag well moistened with plain old brake fluid, they look like new. First time you put it on thick and let it sit... then wipe it off like some folks do wood stain. After that, a very light coat... more like barely moistened, and let it sit does the trick.

I have also heard about unscrupulous used car lots putting an amount of brake fluid in an automatic transmission to rejuvenate the seals and stop leaks... temporarily. I've never tried that, so I don't know if it works, but I do know brake fluid works as tire dressing, and I've never seen a dry rotted tire that had brake fluid applied regularly... like four times a year or so.

Capt Bob
04-30-2005, 04:00 PM
I cover my trailer tires with large trash bags. Also use a protectant with UV properties..Works for me...

Capt Crunch
05-02-2005, 08:21 PM
Thanks for the replies. I never realized that it was the sun, mainly, that apparently tears tires up. :idea:

For anyone interested, someone on another board pointed me to Harbor Freight Tools, which is selling sets of 4 wheel covers for $11 at this site:


05-03-2005, 09:37 AM
Thanks for the link, Capt! Just what I was looking for.

05-03-2005, 10:49 AM
There's more to the tire dry rot problem than UV protection. My truck and trailer tires get the same exposure to UV from the sun, but the truck tires don't suffer dry rot and the trailer tires do. I always thought that the dry rot was from lack of use, but I never knew why. Your post got me to researching, and I found the following from a site dealing with the issue.

There are two main degrading agents that attack tires and rubber trim. They are UV light waves and ozone. Both of these attack the long hydrocarbon chains of the rubber and by breaking these bonds, shorten the molecules with resulting loss of elasticity and other problems. Tire manufacturers add two primary sacrificial protectants to the rubber. To protect against UV, they add carbon black. This is why tires don't come in designer colors to match your paint. The carbon black will turn white/gray as it absorbs the UV and dissipates the energy as heat. Thus the basis of rubber parts turning gray as they age. To protect against ozone, tire manufacturers add a wax based sacrificial protectant. The ozone attacks the wax and depletes it. As the tire rolls, additional wax is forced to the surface of the tire. This is referred to as "blooming". This blooming refreshes the surface wax protectant. A tire that has not been flexed will have the wax depleted by the ozone and thus begin to degrade and suffer "dry rot".

Looks to me that the solution is more excercise of the trailer tires. Which is a scientific basis for justifying more fishing.

303 Aerospace Protectant applied to the tires will protect from both ozone and UV damage, but I still think that regular exercise back and forth to the boat ramp is a better solution.

05-03-2005, 11:56 AM
I keep my trlr. tires protected from the sun, and I use 303 sparingly. Unlike most tire dressings it has no petroleum distillates. Most products like Armoral have short term side effects, but I've found them to dry the rubber out even more, in the long term.

5 yrs. ago I threw away 4 perfectly good tires, which had rotted side walls. I don't wish to go there again, and since implementing the above, the ruber looks like new on this set.

Capt Crunch
05-03-2005, 01:41 PM
Thanks, you found the rest of the story that I couldn't. I was thinking the same thing: Why do trailer tires rot in a few years, but car tires hold up just fine?
You're right, I need to exercise those puppies more. Works for me!

05-03-2005, 05:11 PM
I'm not sure what high tech agents are in the tire treatments everyone uses, but I've kept my trailer tires looking good with minimal care since 1972. I have never lost a tire to dry rot... okay my bicycle in the garage, but I never treated it with brake fluid, and it has gum rubber sidewalls... and who needs all that exercise?

Here's a photo of one of my six year old tires. These came on the replacement trailer from my highway wreck, back in '99. I haven't touched in in some time, but I have treated it about three or four times, in six years, with brake fluid.

Here's the same tire, after rubbing it with a rag dampened with a small amount of brake fluid.
You can see the little nicks in the tire to the left of the "M" on both pictures. When you rub the brake fluid on the rubber, it seems to remove the layer of oxydation and forms a non-liquid protective layer on top of the rubber. It also seems to penetrate the rubber and soften it somewhat.

I know it's sexier to use space age products for boating, but brake fluid is cheap and easy to find. As Jim Heverly learned with the black marks on his coaming bolster... brake fluid is miracle stuff. Makes a great hand cleaner for the nasty black grease and brake dust you get from working on the mechanicals on the trailer. Hmm, wonder if it would treat laundry stains?

Capt Crunch
05-04-2005, 06:21 AM
Thanks for the photos. Do those tires sit out in the sun all year? I may have to try that. Also, which brake fluid? Plain old whale oil?

Hugh Copeland
05-04-2005, 10:21 AM
Charles since brake fluid is water soluable wouldn't it be absorbed into the skin. Does it cleanse ones blood.

05-04-2005, 11:39 AM
Thanks for the photos. Do those tires sit out in the sun all year? I may have to try that. Also, which brake fluid? Plain old whale oil?

For those pictures, I picked the one tire that catches the most sun. Although I can't tell the difference in how any of them look. It will start catching sun about ten thirty, in the Summer, and stays brightly lit until about three thirty. The tires on the other side never see the sun, and the one behind that one doesn't see it until about noon, if my truck is parked next to it. When I go boating, the same tires catch the sun in full, while I'm out from my usual home port. I only drive five minutes each way to the landing, with an additional seven minutes to hit the fuel farm, at the end of the boating day. Those ain't high use tires. Probably five or six miles round trip, each time out.

That is the cheapest and biggest plastic container of brake fluid that Wal Mart sells. Store brand, I believe. If I'm only wipin' tires with it... what the heck. It's worked for that for me ever since about 1969, when I bought my solid black Chevelle SS 396. I put 8.15x15 tires on it with big plain sidewalls, and wanted them to look good. After a little experimentation, I came up with the brake fluid, after spilling some on an old tire at my buddy's garage.

Now, I'm like the dad on the Big Fat Greek Wedding movie. He loved Windex, and I love brake fluid... and PVC... and copper pipe.

Try it, I know you'll like it, and maybe you'll maintain your brakes a little more diligently. Two birds with one stone.

05-04-2005, 11:49 AM
Charles since brake fluid is water soluable wouldn't it be absorbed into the skin. Does it cleanse ones blood.

I may have to go to my health related mailing list and check on that, if anybody over there even knows. I haven't used it as much as engine oil for cleaning my hands, but I also haven't noticed any harmful effects, unless it causes arthritis in the hips and knees and I didn't know it. I don't think it would be very good, if it did penetrate... since it sounds like it's chemically halfway related to antifreeze.

I take enough supplements to counteract almost anything... morning, noon, and supper time... and a probiotic at bedtime.

02-20-2006, 11:59 AM
Anyone have advice as to which brand trailer tires are best? I have 8 yr old Carlisle ST75R-14" L.R.'C' radials on my tandem trailer. There's plenty of tread left, but as most of you have previously stated, dry rot on the sidewalls. I Googled Carlisle Tires for where to buy them & found horror stories in some e-pinion reviews of them. As far as I know, mine are the originals on the trailer since '97, and towed my boat home from Daytona, Fl. over 1100 mis. w/no problem in May '03. Was going to replace them because of the dry rot, but after reading so many nagative reviews, I'm hesitant. There's even a site to register in a class action suit claiming damages from tread seperation and belts coming apart on Carlisles. Also, is it true that from the DOT number on the sidewall, you can tell a Carlisle tire was actually manufactured by Goodyear?

02-20-2006, 01:47 PM

I have a set of Carlisle USA Trail ST205/75D14 bias ply tires on my Load Rite trailer, originals from mid-1997. I (usually) raise them off the ground and cover them during off-season storage to protect them and have had no problems. I've hauled the boat from Phila., PA to Cape Hatteras 6 times in the past 9 years (>900 mi, round trip, including all the towing I do while there) and there have been numerous 120 mi round trips to the NJ shore and upper Chesapeake as well as 3 trips to Southern RI and one trip to Acadia ME since I've owned the boat/trailer. 90%+ of their dunkings have been in salt water.

I had a set of Goodyear F78-14ST's on my previous, much lighter weight, single axle trailer and within 4 years I had sidewall cracking. I replaced them with Carlisles and they were on there until I sold the boat/trailer 5 years later.

My trailer tires are at the end of their tread life (~1/8" remaining) but the sidewalls show no evidence of dry rot or crazing. In the 9 year period I've owned it, I lost only one tire/rim because some little bastich in a "ricer" cut me off as I was leaving a bridge toll booth and I hit the toll island curb when I swerved to avoid him.

All I could find about the Carlisle lawsuit was that two MI guys had some problems and the lawyer is trying to get the suit jacked up to a class action proceeding (prolly to line his pockets more). I saw a couple other blogs but nothing that raised the hackles on my neck. If you have any links to particularly "nasty" reports that seem to really incriminate Carlisle, please post them, I'd be very interested.

From what I've read, and been told by trailer ppl, radials are not really recommended for trailers (even though they make them for that application). They just don't have the sidewall stiffness that bias ply tires have. I can see their point and agree, but don't know enough about the subject to argue it.

I'm getting new tires this Spring (9 years is old enough) and will probably get Carlisles but they won't be radials.

Edit: Did some more searching... It seems that most of the complaints about trailer tire problems are related to RADIAL tires and only a few regarding bias types. This trend also seems to be predominantly about travel trailers. I wonder if the "top heaviness" of that kind of rig aggrevates tire problems. The center of gravity on a towed Shamrock is much lower than that of a "boxy" travel trailer.

Also found this little "splurge" on trailer tires. Wonder how much of it needs to be taken with a grain of salt (particularly the stuff under the "Time" heading):



02-21-2006, 12:35 PM
here's the link: http://www.epinions.com/Carlisle_Radial_ST_Utility_Tire
from: www.epinions.com/auto-Tires-All-Utility_type-Carlisle_brand

I looked there since those radials are my tires, then I wrote my own review. Didn't think it was fair, since you and I both have had no problems in 8+ years. Other than sidewall dry rot, the tires seem fine. I figured changing them now, before one blows out & ruins a good day on the water was prudent. When scrolling down the Google page further, the lawsuit jumped out. I'm glad to hear you've had a good experience with Carlisles. It just looked strange that 9 out of 9 reviews were negative, but who goes out of their way to write when a product performs like it's supposed to? While searching, I called Eastern Marine in Delaware, who said they only sell "LOADSTAR" brand trailer tires, & don't like Carlisles. The salesman there agreed with you, saying most people don't use radials on boat trailers. They don't even sell my size as 'tires only', you've got to buy them on the rims if you want the radials. Can't find who makes Loadstars. What brand are you running Charles?

02-21-2006, 02:59 PM

In doing a bit of sniffing around, it looks like Load Star tires are manufactured by a company called KENDA. Here's a link to their site:


It would appear that KENDA is an Asian (China, Vietnam, Taiwan) enterprise. Don't know about your preferences, but I'm not too keen on Taiwanese, etc. tires (Japanese may be OK, but I'm a little leery of other Asian sources).

In doing some other searches, I found that Goodyear Marathon ST (Radial) tires have their detractors as well. As I mentioned before, it seems that all the b*tching is about blowouts and tread separation with radial tires. Like you mentioned, ppl tend not to write about something unless they've had some bad experiences with it.

Champion Trailers ( http://www.championtrailers.com/ ), in LA, sells unmounted Carlisle tires but I'd guess that shipping charges would be pretty stiff for a set of four form LA to NY (or PA for that matter).

I'll go out on a limb here and guess that Charles' tires are Carlisle Sure Trail bias ply tires. That's what I have for my spare and the tread design looks identical. The Sure Trail tires are 4 ply and the USA trails are 6 ply.

i fish
02-21-2006, 04:31 PM
Just a gut feeling. Trailers are in and out of salt water, right? Tires are in and out of salt water,right?

Does that contribute to or hasten the dry rot process??

Len aka i fish

02-22-2006, 07:00 PM
thanks again for the reply & research. I won't be buying any Loadstars by Kenda. Called the Carlisle customer service line & we won't need to pay $50 to ship 4 tires from Louisiana's www.Championtrailers.com. Your local WalMart stocks Carlisles. If, like in my area, there isn't a WalMart, PepBoys has 'em. There's an article in the 2/16 issue of The Fisherman on long haul trailering. The writer advocates balancing trailer rims to minimize vibration. He states that Shorland'r Trailer shops now balance their rims, & are installing radials rather than bias ply tires for a smoother & more secure ride. I like the link from Capt. Crunch for tire covers for winter storage to help prevent dry rot. You guys on this site are great for helping each other out.

Edit- Ummm, disregard my previous post... On closer inspection today in the sunlight, my trailer has bias ply tires, not radials. I'm not only senile, but must have night blindness. Mistook the D for an R at the end of ST205/75D. And yes, it's a Carlisle USA Trail, as you guessed. PepBoys doesn't have it in stock, of course, but will special order them for $$ more than the radials. Good thing it's still February.