Rust - Sill and rear wheel well

[jansen.fan]

Hi Everyone,

I have a 2008 Yaris in Canada. I've had trouble over the years with rust on the rear wheel well (right) and beneath the rear door sill (right). I've always cleaned the area, gotten as much rust of as possible and then applied sealers, paint etc.

My problem is that the issue has gotten worse. Today I removed all metal that was soft and corroded. See the pictures attached.

My questions:
- The wheel well damage is purely aesthetic, correct? Might I just patch this with some fiberglass and filler? I don't care that much about the looks.
- Is this part of the sill a structural component? If so, will I need to get this welded, or can I get away with simply putting in some fiberglass?

I don't have any facilities for steel cutting or welding, so my choice is to do it myself with fiberglass or send it out. The former is my preference, but I want to make sure I don't have a fatal failure one of these days.

Any input is much appreciated!

[praivo]

This is a unibody car, so both sills and wheel wells are structural. You can fiberglass little holes (<5 cm), but anything bigger than that needs to be repaired properly to be safe. No welding = no repair.

Get a cheap MIG machine (even a flux-core/gasless one should work) and practice a bit before doing anything to the car, or get someone else to do it.

Check the rest of the car, too. If this is that bad, there's definitely far more rust on it, some of which may be hidden underneath the factory undercoating. If it's anything like the first generation, I'd expect rust mainly along body seams. And I mean every single seam on the underbody...

You might like this thread about my T-Sport: http://www.yarisworld.com/forums/showthread.php?t=61169

[tmontague]

It's true that almost every part of a unibody is structural however some parts are lower structural than others.

The wheel wells I wouldn't be concerned about, the door sells would be more concerning. That said, you have "frame rails" that run under the car that are a main point of strength on a unibody do I doubt that those sills are holding to much stress.

Keep in mind that those "frame rails" only run from the front until about the midway point of the yaris frame so those sills potentially may be important.

As stated above, what other trust is hiding in this car? These aren't usually rust prone cars so if it is one area it could be due to a previous accident causing paint damage. Otherwise it could have had water damage and the rest of the car be compromised

[jansen.fan]

Thank you both for your response.

Thanks for the reference instructions Pravo. How hard would it be to do this welding? I have mechanical and woodworking experience, but not a whole bunch with welding and steel. I'd be curious to learn, but I want to get a sense of what I'm getting myself into.

I tend to agree that the wheel well won't be a huge issue. Only the exterior is rusted and I think that's only for aesthetics.

The "frame rails" are pretty rusted as well, so I'm concerned about the sill. I might get a professional opinion on that one.

Would you guys happen to know what something like this should roughly cost?

I'll check the rest of the car.

Thanks!

[praivo]

The wheel wells are structural. The outer half is a part of the sill, and the inner half holds the top of the shock.

There are frame rails (which, at least on the first generation, run from under the dead pedal all the way to the rear bumper. But they aren't as strong as a real frame would be, not to mention that they've probably already lost some strength due to rust. The bottom of mine literally fell out right where they hold the rear axle beam...

As for how much it would cost to have it done by someone else, take the highest price you can think off, double that, add a zero, and you'll probably still be too low. It would probably be more than the car is worth now, because this will be A LOT of work. My sills weren't much worse, and I still spent nearly a week on each side.

edit: It's probably worth mentioning that both my cars are rusty even though at least one has been neither crashed nor submerged. All it takes is some (well, a lot of) salt and not enough maintenance.

How hard would it be to do this welding?

Not really that hard if you practice first and cut all the way to good metal before making a patch (welding on rusty metal is a pain). For me, welding is the easy-ish part. It's making the patches that I've been doing for half a year and still rarely get right.

[DarkShadowFox]

you need to repair those holes with the metal thats reccomended by the toyota repair manual and stuff.

[jansen.fan]

Thanks again for the response and sorry for the late reply.

I got a quote and it was about $5,500. So yes, much more than I had expected.

I'm going to try and weld it and if that fails I'll re-evaluate. I'll probably end up with 18 gauge steel so bending it may be a challenge.

The rest of the car looks just fine with regards to rust. We bought it used and something may have happened around the back area of the car I'm not aware of.

[ex-x-fire]

Make sure use something to treat the non rusting area before they get bad. I like fluid film. You can pour atf down in the rockers & doors. Try to get some into the cradle.

[praivo]

20 gauge (0.9-1 mm) should be enough for almost everything and a bit easier to bend.

DO NOT use Fluid Film or anything similar on the panels until they're FULLY welded. The last thing you want is to set the thing on fire while you're welding. Even oil fumes aren't that great. And don't just pour oil everywhere, use a cavity gun to cover the inner surfaces as evenly as you can. There should be access holes to all the cavities, some may just have stickers over them.

[jansen.fan]

It's like both of your read my mind, as this was my next question. However, I'm not sure I understand the answer.

What should I cover the inside of the cavity with so that it is rust protected, but is not a danger, when I'm welding in the panel. I'm thinking in particular of the cavity right around the outside rocker patch I'm replacing, where I'll want to make extra sure I protect against rust, but where the welding heat will be the worst.

Thanks!

[jansen.fan]

Re-reading your messages it sounds like the correct approach is to weld, and then apply an oil based film to prevent rust in the cavities. I'll do that.

And I can use some of the weld thru primer, on the backside of the patch. Apply it before welding and it should be safe.

[praivo]

Yes, weld it first (after priming) and then spray. Trust me, I tried to do it the opposite way and it sucks - you'd have to go extra slow and spray air into the cavity to cool the inside. That gets annoying after about the first two tacks.

[jansen.fan]

Great, I'll do that. Is the finish inside the cavity that is on the car right now, flammable? If so, how far away from the weld seem will I have to remove it to avoid problems there?

[alanwagen]

I know it's a hard choice but I advise that you cut your losses and replace this car. Nothing is forever and there are a lot of good condition and good value Yaris cars being sold by the car rental places.

[praivo]

jansen.fan: The only thing you really need to remove is the undercoating on the underbody. It will catch fire, ruin your welds, or both. The cavities should be fine, removing the paint on the outside should be enough.

alanwagen: That can be done at any point if OP finds it too hard to repair. But rentals aren't known to be taken care of very well, so I'd prefer fixing a body on an otherwise functional car over getting a "clean" one with drivetrain/electrical problems.

edit: On top of that, these thing rust from the inside, so there may be no rust outside but the inside may already be missing half its metal. I, too, learned this the hard way.

[jansen.fan]

OK, I'll remove the undercoating and go from there. If all goes well I'll attempt some work this weekend.

I'd like to try an salvage this car, unless it become really bad. The car is in good shape otherwise, so it would seem like a waste.

[alanwagen]

I disagree about rental cars. They are maintained and they come with a warranty. My son has bought 2 and he has not had any repairs and no oil usage.

[WeeYari]

I disagree about rental cars. They are maintained and they come with a warranty. My son has bought 2 and he has not had any repairs and no oil usage.I'm with you on rentals. I don't know how many times I've stood on my soap box and endorsed my own ex daily rental. It is now 13 years old with 337,000 kms logged. Only failure I've had is the known issue of the voltage regulator in the alternator. Hell I'm even still on original bearings, links and bushings.

However, the poster commenting on stay away from them seems to be in the Czech Republic Maybe there rentals are subject to abuse, unlike here where they are often better maintained than privately owned.

Sent from my EML-L09 using Tapatalk

[komichal]

I am from Czech Rep too and I do agree that the rental cars here are a risk. You may get lucky and get a good car but most of the rental car drivers here are assholes, their attitude is "it is not mine so I can turn it into junk and I do not care".

[praivo]

So, how are the repairs going? I'm getting ready to take the front of my TS apart to repair the front frame rails and replace the subframe.

[GrayYaris]

And I thought I was the only one. I have a 3dr with rust in similar areas (I'm in CNY). The biggest mistake I made was grinding down the paint, hoping for an easy repair. What I found was a lot of holes, due to the body parts rotting from the inside-out. The body is really thin gauge steel in some areas, making a little bit of surface rust turn into a hole rapidly. For some reason a lot of salt and road grime gets sprayed on the right side. I wish I had sprayed fluid film inside the rockers and all over the unibody when I purchased the car.