6 replies to this topic

[gerwulf]

seeing as my car will be my daily driver, in winter too. is it better to oil the underside, or to use undercoating?

[Indiana]

The bottom side of the car isn't the problem.  Suspension parts rust, just best to drive by the car wash once a week and flush it off.  Its the bottom enclosed edge of the rear quarter panels and the front fenders that you need be concerned about.  There's plastic plugs over holes that leak and those areas rot from the inside out.

You would be wise to remove the bolts from the bottom edge of the fender and the plastic apron and pull it out, flush it and make sure its not rusted and protect it from getting worse.  Water and crap from the cowl runs down the sides and is to be able to get out two slots at the bottom of the fender and they are usually full of crap and then this doesn't dry out and with salt in there it just eats away 24/7.  For the rear quarters, you have to remove the interior and take out the seat belt motors to get to that space, its all open from the inside but that gets about a half inch of wet sandy salty crap in it and it takes longer to dry out until its full of holes and gets to drip out the bottom.

[Burton]

What he said... Plus I'll add that if you're getting in and cleaning the back sides of the panels that rust, take the time to also coat them in POR15 or some other rust inhibitor. That will slow down any rust that has started, and keep away rust that hasn't.


As far as the undercoating or oil debate.... I prefer undercoating as long as it's done well. Undercoating put over moisture, salt residue, or already growing rust won't help much. Make sure the whole underside is extrememly clean, then treat any rust spots with Por15 or the like, then let everything dry out real good so there's no moisture left behind. After all that, coat everything with a quality rustproofing or some spray on bedliner material.

Oil is OK to use, but it gets flushed away quicker than you think. In order for it to be good protection, you'd have to re apply frequently, and that not only gets to be a lot of work, but you're also puting all that oil that washes off into the environment.

[DMNDSTAR87]

Even undercoating is not the greatest---moisture can still get underneath even the best brands of undercoat and once moisture gets under it(and it will)it will  rust and by the time you notice it will be too late---dont get me wrong undercoat is easy to use and inexpensive and does offer some value but if you drive all season i would recommend por15 products----little pricey but worth every cent---just my opinion--
gig out

Edited by DMNDSTAR87, 12 September 2011 - 11:49 AM.

[gerwulf]

ill look into that por15 for undercoating

[Rich]

I live in Meadville. I don't know whether oil or undercoating works better, but I have Maillard's oil all of my cars (except my Starion) every fall. The Starion doesn't see wet roads. It costs about $60 per car, but you can definitely tell a difference over the life of the car. I've never started oiling on a car that already had rust so I'm not sure how well it works in those cases.  

They have been doing it for 40 years. They have couple of different options, but no matter which one you choose it's pretty messy for a couple of days. Don't put the car on a nice driveway for a couple of days. They oil until the end of October. The best time is AM during the week. They get really busy on the week-ends, but they get people through pretty fast.

They are at 27370 Lippert Rd, Cochranton I think. 425-3600. You don't have to make an appointment, but I'd make sure they know what you want them to oil (and not to oil), otherwise they get into the hood, door holes, around the engine, pretty much everywhere they find metal!!

Indiana, one of the problems we have in NW PA is that it's pretty hard to get a car washed (unless you have a heated garage and a power washer) between December and mid-March. Everything is frozen up for months.

Rich

Edited by Rich, 14 September 2011 - 06:15 PM.

[gerwulf]

ya pa is a prob for that, and with you having to go up decent sized hills just to get out of franklin, its gonna be a pain