I have freed my Bird from the garage for a few days during the half decently mild weather we have had in my hometown and I am thinking about undercoating my car. Is it a good idea? Has anyone else done this? If so, what method and/or brand did you use?

 

bump

 

I, personally, hate rubberized undercoating in most cases. It can, and I know this from experience, crack, allow water to get under it, and cause widespread rot. It is also a nightmare to remove it if you ever find the need to.

If you want to protect your floorpans, I'd use a product like Master Series. POR 15 is similar and more popular, but I use Master Series instead.

 

Take this from somebody who has worked in the New used car indastry and Autobody indastry. THe best and only time you want to put undercoating on a car is when you buy it brand new off the lot. Sure Mabie after a ground up resto when you have everything stiped down would be a good time but who relaly wants a restored car with undercoating.

Nothing will speed up rust faster then tar undercoating. In the course of as little as two years (severaty of rust depending) turn a car that had an very exseptable problem into a rust bucket. When I started working in the as a new car detailer we had a newish Mitubishi SUV come in to get undercoated after a year out on the road. There was A few serios rock dings on the floor boards and we advised the owner not ot undercoat. we where basicaly told to Do what we where paid for. With in two years the veicals had soft spots on the floor and rust starting to creep up the quarters. Not very fun. espetaly when there was a great deal of the exact same veical out there that have no rust problems. Food for thought. Don't undercoat. Unless it's new.

 

Don't do it! Especially if you work on the car, as the undercoating makes it hell to work on.

 

my car already had an undercoating when I got it. But I would say just take the time to clean under there with a pressure washer or something.

 

no undercoating but por-15 has worked great for me. i've had it on my 91 z28 for 5 years and it has worked as promised. i recently put it on two of my cars that i rebuilt and sold. advise not getting it on bolts.

grind up your rust, smooth everything so that it looks nice and clean. some rust showing is ok as it sticks better and paint away.

i can do a whole underside with half qt. and 2-3 disposable brushes. good luck.

 

The job has been completed. I cannot remember the name of the undercoat that was used. Rust free something anyway. They even put it in the doors and the engine bay. It seems the provide ample protection against the rigors of winter. In my area, salt is used on the street during winter and not the conventional sand. Even though I don't drive my car during those times, the salt lingers on the roadside long into the spring. So I pretty much had to undercoat. Thanks for the imput guys, keep it coming.

 

You could try zero-rust. It's a bit thinner and more primer-like, but it's half the price of por15 and usually available at napa.

 

So, you went ahead and got it undercoated? I hope it works for you, man, but as I and a couple others have said here, it doesn't always work. I personally have seen it trap moisture and rot out parts of cars. And if it does cause rot, you will have a heck of a bad time trying to clean the area to cut out the rot and weld in a patch.

They use salt here, too. I wash my cars once a week, regardless of temperature, and the wash includes the undercarriage and wheelwells.

 

Ya, it was already done before I decided to get opinions on here. Its not a thick undercoating though as my car is a summer car of course. It may cause some trouble with some part removal, but that is yet to be seen. I have a question though, where is the most common part(s) where moisture would become trapped?

P.S: Its not rubberized, its just a spray on applicant.