OMG, I know no one is going to want to touch this one!

Automotive tires are hot vulcanized rubber, no? As opposed to RTV (Room Temperative Vulcanized). Hot vulcanized means molded/set under heat and pressure.

Okay. You have a defect in a tire you got at a junk yard ICARUMBA!. What to do? Is there a commercially available adhesive that can be used to patch a gouge, say no bigger then .75" across, approaching 1/8" deep? Come on humor me. This a commonly asked question if you pull up a google search. Some try RTV, others give elaborate procedures.

If to be successful, it stands to absolutely thoroughly clean the area well (brake parts cleaner? Ammonia (best damned penetrant I've ever seen, but needs a long time (24-48 hours) to do it's job)? Then you need something that will in effect "hook" the rubber, pulling it together as it cures, and will stay reasonably flexible. What about dissolving some actual tire rubber in a solvent, and applying layers of that?

Come on guys you know this thread will make for loads of fun.

There was mention somewhere of cleaning, using a filler, then putting a patch over that. That makes good sense to me, as a patch will just reinforce the reinforcing filler. Theoretically there is no reason this job can't be done. The question is how.

What about melting some tire rubber, and dribbling that on the area? Tire rubber does melt, this I know!

Me, I'd ask the yard to swap it for another.

Anything deeper than a gouge to the cosmetic outer hide of the tire will compromise it's integrity. Nothing you do can change that.

Not sure what you're looking at, exactly.

We are talking SAFETY here...you do not want a tire blowing on you, especially at highway speeds....don't repair, replace....

You have a defect in a tire you got at a junk yard ICARUMBA!. What to do? Is there a commercially available adhesive that can be used to patch a gouge, say no bigger then .75" across, approaching 1/8" deep?
Defect in tread area, patch from the inside or simply don't worry about it if it doesn't leak.

Defect in the sidewall--tire is junk. Buy another one.

If you have a 1/8 inch or less piece of the tire scraped off the side wall, and the tire has no bulge on the area then just put some black rubber sealant on it. use soapy water to smooth out. also using some thin clear plastic with silicone on it smooth it more.

If this tire is damaged deeper than the 1/8 in then go back and get another scrap tire.

using a hair dryer will speed up the curing but it will take 24/48 hrs to be completed. driving on it too soon it will break down.

sealants especially comercial stuff flexs quite well.

if you can see cord/or steel its junk.

"using a hair dryer will speed up the curing but it will take 24/48 hrs to be completed. driving on it too soon it will break down."

I can always pull the tire and let it sit for that long. But is it better to do this inflated or deflated? How many hours of driving would you put on such a (rear) tire if done properly?

"sealants especially comercial stuff flexs quite well."

any recommendations?

"using a hair dryer will speed up the curing but it will take 24/48 hrs to be completed. driving on it too soon it will break down."

I can always pull the tire and let it sit for that long. But is it better to do this inflated or deflated? How many hours of driving would you put on such a (rear) tire if done properly?

"sealants especially comercial stuff flexs quite well."

any recommendations?

post a picture of it. put the spare tire on for a few days. leave it inflated in the sun for cure.

Melted rubber won't cure without mixing in a little sulfur, but don't mess with it. How much is a junkyard tire worth, vs your life?

Or how about someone else's life?