Grading--what am I doing to cause this?

[PILOON]

To obtain a nice flat graded road you need a flat reference to work from otherwise every dip or bump will be magnified.

One sure way (you won't like it) is to drive backwards while 'grading' or spreading new gravel.
I have spread truckloads of gravel for great distances often to a desired , say, 3 inches of coverage.
Now if I wanted a super finish I often dragged my blade reversed at a moderate speed and you'd think it was a hand raked finish.

Hills are the worst as most drivers don't attack them properly.
They should accelerate B4 the hill and coast up but most tend to slow down and let the transmission shift down which then starts a small 'bump' which magnifies as more cars drive up resulting in washboards.
With an automatic tranny downshifting and accelerating B4 attacking a hill will greatly preserve the graded finish.

LOL, but then heavy rains will erase all your good grading skills.

 

[3 Horse Ranch]

Don't have a harrow, I could do it in drag and that would be a pretty harrowing experience, would that do? Had to look up '3/4 minus', thought it was a typo, that would be great but I don't want to spend any money on this, it's good enough for for me. What do you mean by '4" to dust'? Can't figure that out. Where I'm at it's all limestone with a little soil or weathered limestone between the rocks, if there is a between. There can be large slabs in places or just lots of smallish rocks mixed with bigger to a lot bigger. Fortunately, where the road is is mostly the smallish.

Sorry, I worked in the gravel and aggregates industry so I just automatically assume everyone knows what I am talking about. 4 inch to dust is the description of the sizes of material, properly it should be called 4 inch minus, i.e. everything that will pass through a four inch screen, four inch stone to fine sand and rock dust and everything in between. Here is seems they use screened natural talus from the limestone mountains, it has a lot of the finer material and is a little short on the intermediate size rock. I doesn't smooth out all than well and bigger rock gets pulled up and either lays on top or leaves gouge tracks if the rock gets caught between the blades of my box blade. I have a half mile of that and covering it with even base course gravel (1-1/4 minus) would be cost prohibitive.

 

[OhSarg]

Use the box blade at a slower speed and use the hydraulic lift like a surgeon

 

[Ken Kegris]

Gauge wheels would be a great help. Always try and have a blade full of material, that will fill in the low spots as you go. do not try and fix the driveway in one or two passes, go back and forth many times with different blade angles. Remember keep a crown in the road. It actually appears that you dont have enough material in front of the blade.

 

[mechtheist]

Washboard is usually at intersections where traffic speed changes dramatically and/or on steep inclines where wheel slippage gets them started.

The OP's problem is blade chatter.

Interesting to read all the posts and theories. All must be taken with a grain of salt. My roadbed type isn't like the OP's or like most of the posters. We should always consider that. What works for me might not work for the OP.

I've maintained 16,000 miles of gravel roads in NW Missouri over the past 32 years. But I don't know how to maintain his Texas road. I know theories and can offer suggestions that would work for me.

My first is to do the maintenance when the roadbed is damp. In the pic the roadbed is wayyyy too dry.

Interesting discussion though.

Wow, 16K miles is a LOT of miles, it's almost 100 times as many miles as feet I have to deal with. Whenever I need to learn something new, I'll ask or read up on it trying to find as many sources as possible and then try to figure out what makes sense, what doesn't or is irrelevant and distill what seems like the best approach/answer for me and my situation. It's almost always the case that the more different perspectives you can get the better a solution you can come up with. And yeah, the road is way too dry/hard AF to do anything with except a lot of chattering.

 

[mechtheist]

Use the box blade at a slower speed and use the hydraulic lift like a surgeon

You mean like try to yank someone's appendix out unnecessarily or just play god and be overly pleased with myself?

 

[mechtheist]

Gauge wheels would be a great help. Always try and have a blade full of material, that will fill in the low spots as you go. do not try and fix the driveway in one or two passes, go back and forth many times with different blade angles. Remember keep a crown in the road. It actually appears that you dont have enough material in front of the blade.

All good advice. What you're seeing isn't the result of trying to do it in a few passes, that's about 5 days of me going up and down my drive trying lots of different things, I wouldn't even want to know how many passes I actually made. Partly it's also due to the road drying too much while I was still working on it.

 

[mechtheist]

Sorry, I worked in the gravel and aggregates industry so I just automatically assume everyone knows what I am talking about. 4 inch to dust is the description of the sizes of material, properly it should be called 4 inch minus, i.e. everything that will pass through a four inch screen, four inch stone to fine sand and rock dust and everything in between. Here is seems they use screened natural talus from the limestone mountains, it has a lot of the finer material and is a little short on the intermediate size rock. I doesn't smooth out all than well and bigger rock gets pulled up and either lays on top or leaves gouge tracks if the rock gets caught between the blades of my box blade. I have a half mile of that and covering it with even base course gravel (1-1/4 minus) would be cost prohibitive.

4 minus, makes perfect sense now. I did get a lot of rocks getting pulled up and doing the long gouge thing. The more I went over the road, the more rocks would pop up. I think the wheel thing with a very small height of the blade above the surface would work to clear those without me having to go out there with a rake.

 

[mechtheist]

To obtain a nice flat graded road you need a flat reference to work from otherwise every dip or bump will be magnified.

One sure way (you won't like it) is to drive backwards while 'grading' or spreading new gravel.
I have spread truckloads of gravel for great distances often to a desired , say, 3 inches of coverage.
Now if I wanted a super finish I often dragged my blade reversed at a moderate speed and you'd think it was a hand raked finish.

Hills are the worst as most drivers don't attack them properly.
They should accelerate B4 the hill and coast up but most tend to slow down and let the transmission shift down which then starts a small 'bump' which magnifies as more cars drive up resulting in washboards.
With an automatic tranny downshifting and accelerating B4 attacking a hill will greatly preserve the graded finish.

LOL, but then heavy rains will erase all your good grading skills.

I'm lucky that my drive is really fairly flat and even heavy rains don't do much of anything to it except in a few places.

 

[kpsp50]

Have a 12 foot long grader blade 8 foot wide home made tilts in every direction used a mobile home axle and 400 # of weight it solved my washboard problem. Good luck