courierguy
MEMBER
Inkom, Idaho
I mentioned on another thread a few days ago I was getting concerned about the number of cuts in my 29" Airstreaks, and had heard vague rumors about others using brush on bed liner as a stopgap measure to maybe slow down the damage.
Bob Breeden makes a good arguement for running less pressure to allow the tire to hit the rocks softer, I had been running 6 lbs. but after trying as low as 3 lbs I have now settled on 4 for my local ridgetop landings. At 3 I could barely push the 740 lb plane out of the hangar, the increase in rolling resistance was nice on landing, but a lot of work otherwise. So, no more 6, but not as low as 3, keep in mind these numbers may not extrapolate directly to you Cub guys using the standard Bushwheels, the Airstreaks on my lightweight bird are built for lighter planes and may have thinner more flexible sidewalls?
So after thinking about it for several days, and really not wanting to somehow ruin my tires by a half ass experiment, I decided to try it anyway:roll: NAPA had several brands of bedliner, the stuff that caught my eye is a Dupont product, and it prominently states on the label MADE WITH DUPONT KEVLAR, MADE KEVLAR STRONG. It was also the most expensive, 40 bucks a qt. I washed the tires with soap and water, then after drying wiped them good with Xylene, they have never been so clean! The goop needed vigourous stirring as it had clumped up in the can, I also stirred it every few minutes during application. I put the first and subsequent coats on with a brush. I waited a couple hours between coats. I think I ended up putting on 4 coats in all, and I think that several light coats is better then fewer heavy coats. It looked good, just added a slight amount of texture to the tire but not enough to grab hold of mud. You can see where I stopped alongside the sidewall, appearance wasn't a concern.... In between tire coats I decided to do my rocker panels on my pickup, right behind the front wheels. I kept putting coats on the tires and the pickup until the qt. was gone, and decided that was "just right". I waited three days before flying it, and kept it on the jacks while it cured.
The good news is it didn't fall off the tire as soon as I rolled it out of the hangar! I also can't see it somehow flying off all at once and going in the prop, too grippy for that. After rolling it out on my concrete ramp I made the usual taxi up my gravel driveway, turned around and tookoff the grass strip. I landed in a couple cut mountain hayfields on the way to the first real test, a 7200' ridgetop where I know from past experience has pretty much worst case type embedded shale rocks, though I do have a place picked out that avoids the worst of them, the narrowness of the ridge means the turnaround has to be pretty tight and that is how I have cut them before.
Upon landing back at home, I saw one spot where the bed liner was bit scuffed from a rock that I had turned on after landing so I could get sideways to the slope before putting the parking brake on and getting out, otherwise the stuff seems to be a sucess. Time will tell, but here's the good thing: though I can't read the label anymore (covered up) I remember it made a big deal that AT ANY TIME AFTER INITIAL APPLICATION TOUCHUPS CAN BE DONE, or words to that effect..... So, I think that every now and then I will do just that, the stuff sticks to itself real well so no need to Xylene again, just soap and water clean should do it.
All in all I'm happy with it, at least I have have the feeling I've done all I can, using the bedliner and running lower pressure. Not flying into these sites at all is not an option, they are way too much fun!
Bob Breeden makes a good arguement for running less pressure to allow the tire to hit the rocks softer, I had been running 6 lbs. but after trying as low as 3 lbs I have now settled on 4 for my local ridgetop landings. At 3 I could barely push the 740 lb plane out of the hangar, the increase in rolling resistance was nice on landing, but a lot of work otherwise. So, no more 6, but not as low as 3, keep in mind these numbers may not extrapolate directly to you Cub guys using the standard Bushwheels, the Airstreaks on my lightweight bird are built for lighter planes and may have thinner more flexible sidewalls?
So after thinking about it for several days, and really not wanting to somehow ruin my tires by a half ass experiment, I decided to try it anyway:roll: NAPA had several brands of bedliner, the stuff that caught my eye is a Dupont product, and it prominently states on the label MADE WITH DUPONT KEVLAR, MADE KEVLAR STRONG. It was also the most expensive, 40 bucks a qt. I washed the tires with soap and water, then after drying wiped them good with Xylene, they have never been so clean! The goop needed vigourous stirring as it had clumped up in the can, I also stirred it every few minutes during application. I put the first and subsequent coats on with a brush. I waited a couple hours between coats. I think I ended up putting on 4 coats in all, and I think that several light coats is better then fewer heavy coats. It looked good, just added a slight amount of texture to the tire but not enough to grab hold of mud. You can see where I stopped alongside the sidewall, appearance wasn't a concern.... In between tire coats I decided to do my rocker panels on my pickup, right behind the front wheels. I kept putting coats on the tires and the pickup until the qt. was gone, and decided that was "just right". I waited three days before flying it, and kept it on the jacks while it cured.
The good news is it didn't fall off the tire as soon as I rolled it out of the hangar! I also can't see it somehow flying off all at once and going in the prop, too grippy for that. After rolling it out on my concrete ramp I made the usual taxi up my gravel driveway, turned around and tookoff the grass strip. I landed in a couple cut mountain hayfields on the way to the first real test, a 7200' ridgetop where I know from past experience has pretty much worst case type embedded shale rocks, though I do have a place picked out that avoids the worst of them, the narrowness of the ridge means the turnaround has to be pretty tight and that is how I have cut them before.
All in all I'm happy with it, at least I have have the feeling I've done all I can, using the bedliner and running lower pressure. Not flying into these sites at all is not an option, they are way too much fun!