Thanks to Bob Caffee for his ongoing maintenance tips.
Recently I toured a retread facility here in St. Louis. Before this tour I probably would not have put recaps on my truck, but after seeing how tires are retreaded I have had a change of heart. So here is my take.
Retreads are called many things like recaps, caps, and retreads. These are all correct, the process it takes to get the job done is much more intensive than I had imagined. This is what I learned from the guys at MFR Tire Services, Jerry Robinson the plant manager, and Michael Bajier one of the owners. This is a Bandag retread facility. There are many brands of retreads but Bandag seems to be the most common. Not only do they do retreading here but they are a full service tire shop with many major brands of new tires.
First we must learn a little about tire construction. The tread is obvious, this is what we ride on, provides traction, and is what the DOT measures during an inspection. Under that we have the belt package, this is the wound steel cables that provide the strength and damage resistance. If you have ever blown out, seen a blown tire or worn a tire to the “cords” the wires you can see are the belt package. Cords are an antiquated term from before there was steel in the tire, and the tire was made from rubber and fabric cords. You can still buy tires with this construction they are called bias ply tires, mostly for low speed like mowers, ATVs and the like. The belt package is under the tread and wraps around the sidewall to the bead. Sidewall being the area where the size, brand, and other information is printed. The bead is where the tire contacts the wheel. The tire in a worn out condition is referred to as a casing. This is very basic and if you want to learn more there is lots of good information on the Web, just Google tire construction.
Every part of a tire can be repaired, depending on the size of the damage. They had a demo tire to show the damage sizes that can be repaired, wow, you need to see this for yourself. A hole 2″ X 3”, a cut 1/2″ wide and 5″ long in the sidewall, a puncture of at least 1/2″, it might have been larger, through the tread.
Worn and damaged tires come in the “back door” for sorting where they are stacked and put in the waiting line. They are then visually inspected and all nails, rocks and other road debris are removed from the tire. The tire will not touch the ground again until it is rejected or finished. Then they are sent on to the machine that grinds the leftover tread down to about 5/32nds of an inch of rubber over the belt package. This machine is computer controlled to mill each tire to the manufacturers original shape and height, every tire is not the same even though it may be the same size. This milling or grinding leaves a surface that the new rubber needs to bond to. Once the tire is milled it will not be touched by bare hands, because you leave oils from your skin when you touch things, oil could cause the tread to not adhere to the casing.
The tire is then inspected again using electricity, the tire is rolled in place with a device inside it that will send an arc through any nail hole or damaged place in the belt package or the sidewall. These places are marked for later repair. The tire is then taken to the skiving station, this is where all damaged spots are ground out and readied for repair. All holes are drilled, using a bit that resembles a round file, to remove any possible rust in the belt package. This is also where large damaged places that need more than just a patch are repaired, these repairs are called sections.
The patching station is next, any patch that is not a Bandag patch will be removed and replaced with a Bandag patch. The reason for this is most tire shops do not repair a tire the way Bandag would have it done. Not saying the repairs aren’t quality repairs, but a plug/patch is the best way to repair a damaged/leaking tire, most shops don’t plug holes before patching. The plug is necessary to prevent moisture from entering the tire casing and causing rust and possible early failure in the belt package.
Once the patches are all installed, the final pre cap inspection is done. Any skiving that was done, the repairs are filled with new rubber. A thin layer of new rubber is then rolled onto the casing. This new rubber is what the new tread will stick to, kinda like a layer of glue. From here the tire is ready for it’s new tread, the tread is chosen by the owner of the tire for the use it is intended. I’m not sure how many different tread patterns there are but there many. The tread is aligned and measured to each casing, for an exact fit. There are full circle treads but we didn’t see this process. The treads we saw have a seam that is put together with gum rubber, all hand fitted, the guys doing this seemed very good at their job, and they seemed to be proud of the job they do. Were not quite done, we must still cook them.
This is the last part of the process, with the new tread on the casing the tire is put inside an envelope, seated to the beads then the envelope is evacuated, or the tire is put in a vacuum inside the envelope. The vacuum must remain during the final cooking stage, if the vacuum leaks off the tread must be removed, so the process starts over for that tire. Each tire’s envelope is connected to a gauge outside the cooking chamber. The cooking chamber or oven, will hold 20 tires, the guys watch these gauges closely as there is a point of no return for fixing the vacuum leak. After the tire has been cooked for the prescribed 4 hours and 20 minutes the tire goes to the tire painter, he puts a coat of tire paint on the sidewalls making the tire look new. He then puts a tag, describing who owns the tire, what tread, the size, and date of retread, on the tire then stacks for shipping.
Most people have a poor opinion of retread tires, and there are some retreaders that don’t do a good job, but it seems to me this reputation is undeserved. As you drive down the road you will see treads on and beside the road. A study was done and the treads you see are about 50/50 new/retread, and most have blown because of casing failure caused by a run flat condition. The tire industry says 15% low pressure is now considered flat. When you see steel with the tread it is casing failure not the cap coming off. The average warranty adjustment for a new tire is just over 1%, for a retread it’s less than .5%, which means a retread is actually a better built tire. With that said you must have a good casing to make a good retread.
The average one truck owner operator does not have the time to pull the tires off, send them to get capped, and a week later put them back on, but if you need tires and are going home for a week or so, this could save you a lot of money. Retreads have just as good a nation wide warranty as new tires at half the price or less. Most retreaders also have an exchange program, if you don’t have the time to wait for your tires to get capped, you can swap your tires for retreads of equal or greater value casings, for a quick turnaround.
If you would like more information about retreads or would like a retread plant tour here is a good resource.
Retread Tire Association/RTA
900 Weldon Grove
Pacific Grove, CA 93950 USA
Toll free 888-810-8861
www.retreadtire.org (A GREAT SITE TO BOOKMARK AND VISIT OFTEN!)
I DRIVE ON RETREADED TIRES BECAUSE RETREADING IS RECYCLING!
This man is very passionate about caps. Think you will like the tour, very good information, should give you a different opinion on recaps.
Until next time keep em rolling with good tread.