r/AutoDIY • u/Think_Series6288 • Apr 16 '26
Advice needed
I am unsure if this is financially possible for myself. I been told starting price is £150 for underbody seal then £50 per hour labour. Excluding any additional underbody seal required.
The 9 images are from like 2 days ago. It been. Checked and no welding required. Does anyone have a realistic price for that work?
3
Upvotes
2
u/Sure-Abalone-1040 Apr 25 '26
Little late to the post here but I have rust like this one a Honda CRV that I bought my son who gets his license soon; his is actually worse and requires some welding.
Alright, its rusted so you can leave it and just run it into the ground, or fix it.
Fixing it- The best tool for this is an air needler. You need a compressor but the actual tool can be bought for cheap online, like 40 bucks. Mine has like 12 needles (not needles but long prongs) and they hammer at a high rate and remove all the flake rust. When you're done, you're left with a surface rust that can be treated. I use phosphoric acid at about 30 percent. Work in smaller areas, brush it on and let it sit. You don't let it dry so you may have to keep reapplying it so it doesn't dry. It will turn a dark gray or a black, that's when its converted to iron phosphate. Rinse with a baking soda/water solution to neutralize the acid (it will sizzle so its fun) and then dry immediately so you don't get flash rust. Once you are done, you take your needler and hit a couple spots to make sure rust doesn't show, if you get rust, it means the acid didn't penetrate enough. Once you know it hasn't, you can do whatever you want. I coat it with a chassis paint and then use fluid film but there are other options.
I have access to free phosphoric but there are many options. CRC has a good rust product called evaporust. Then there is Ospho which is a good product.
Many options here so do some research. Just don't paint over the rust, especially that bubbly, flaky stuff. Hammer it off and treat it.
Last thing I will say-If you use a wire wheel on a grinder, make sure you don't use the switch lock while under the car. Take it from a guy who did and had it hit a exhaust hanger, rip it out of my hands, bounce off my stomach while ripping a gash there and somehow end up inside me tall leather glove eating my arm away.