How I finally solved the custom driveway ramp problem — steps that actually worked

I followed this exact method last summer beacuse my driveway has a nasty 4-inch lip that was scraping the undercarriage of my sedan. I ended up getting a 5-gallon pail of the Rosehill TPV binder after seeing it used for track surfaces. The 1:5 ratio is definitly the sweet spot, but I found that if I went slightly heavier on the binder—closer to 1:4—it handled the heavy rain we get here much better without the edges fraying. The soapy water trick is a lifesaver. I used a cheap plastic garden sprayer filled with Dawn and water to keep the trowel moving. One thing to watch out for is the temprature. I tried a small patch when it was about 90 degrees out and the stuff started "skinning over" way too fast. Stick to a cooler morning or evening if you can.

I used recycled SBR crumb from a local industrial supplier, and after letting it sit for a full three days, it's solid as a rock. Even with my SUV going over it daily, it hasn't shifted an inch. It definitely beats those $100 pre-made ramps that always seem to slide around.

I'm totally new to this and don't know much about construction materials, so where do you even go to buy those 'SBR crumbs' or the binder? I checked my local hardware store and they just looked at me like I was crazy.

Also, how fast do I have to move once I mix it? If it skins over in the heat, do I only have like ten minutes to get it in the mold? I'm worried I'll be too slow and end up with a giant sticky mess on my driveway.

To address the sourcing inquiry, you typically won't find specialized aromatic or aliphatic polyurethanes at a big-box retailer, so you shold instead search for local landscape surfacing suppliers or athletic track installers who often sell surplus pails of MDI binder. Regarding your working time, the 'open time' or induction period is highly dependent on ambient humidity since these are moisture-cure systems, meaning that while you might have thirty minutes in a dry climate, an exceptionally humid morning coud accelerate the cross-linking process and cause the mixture to become unworkable and stringy much faster than you initially anticipate.

Quick update — I finally tracked down some aromatic binder from a local track installer like suggested. That Rosehill stuff is great, but even with the soapy water trick, I'm still struggling with the mix sticking to my drill paddle. It’s a mess to clean. Does anyone have a better way to strip the cured resin off metal tools without using harsh chemicals?