I will be taking my car to Krown for the first time, and somebody told me that they drill holes to get to the inside of the panels. My car is a Chevy Cruze if that makes any difference. What are your thoughts on this? Should I get the holes drilled or get it only sprayed underneath? I am very particular about my car, however, I do not want it to rust out. I live in a place with harsh winters and lots of salt on the roads.
They put plugs into the holes. My 1994 Mustang got this done back in the 90’s and the rocker panel has zero rust to this day. Same with the bottom of the doors.
Yup!
I had this done to my '81 Citation, and when I got rid of it there was no rust in any area, including the rocker panels. However, the car was such a mechanical disaster area that–despite the absence of rust–I opted to dump it after 5 years.
My Riviera had the Rusty Jones treatment and they put plugs in. Never had inner body rust but that didn’t stop the rust on the pinch weld areas. You have to remember that the current cars are heavily rust proofed on these hidden areas anyway from the factory. Can’t hurt I guess but don’t think it is really needed. Plus my Riv had the lower sheet metal galvanized and that was a few years ago. If you are going to get into the hidden cavities, you have to drill holes to get the spray wand in there or take all the interior trim off.
As long as the exposed metal (after drilling) is treated with appropriate rust proofing, drain holes will likely improve the rust situation, and shouldn’t cause any major problems. This isn’t something I’d do proactively though absent clear evidence rust problems were beginning to set in.
You might want to take a look at a recent issue of Hot Rod magazine (October 2021 I think) one of the articles is about correcting a rust problem in a truck’s cowl area (engine compartment, directly under the windshield). They removed as much of the rust as they could using a wire wheel, then some replacement sheet metal, drilled some holes for drainage, rust proofing, done.
The holes are drilled to allow access for the sprayers to spray inside the doors, etc. They don’t put holes in to drain the cavities.
Really though I used some wax type coating from NAPA when I re did my door. You could do it yourself by taking the door and back panels off. Also I used a product called Rocker Schultz on lower exterior surfaces to guard against sand blasting. Spray it on and paint over it. Very tough stuff.