91 Regal rear bumper reinforcement bar repair - I have a question

[Dinsdale]

It's a straightforward job now that all the elements have been split. The front (as it sits on the car) of this bar will be covered with a single piece of sheet steel, as per the original. One of the photos attached shows a bit of the old panel, with factory-cut holes.

 

I can't decide whether to add these holes to the replacement panel, to keep the car looking original, or to dispense with the holes. The former route would enable water to get in and around but make it possible for an annual refreshment of rustproofing treatment. The latter route of a closed panel would keep water out but not allow future access.

 

I'd be grateful for comments and opinions on this dilemma, before I get going on it on Tuesday.

 

Either way, it's going to be in a much better state than it is now .

 

Cheers!

 

 

Note, for anyone who might do this job:

 

The mounting brackets with the captive bolts were spot welded to the original large piece of steel I am replacing, and the large panel then spot welded to the reinforcement bar. There are no direct welds between the mounting brackets and the profiled rear section of the reinforcement bar, and this made it easy to strip the whole thing down.

Edited October 26, 2014 by Dinsdale

[Cutlass350]

Keep/make any holes that are needed for bolt accesses. Otherwise, don't add holes, or bother to make it look like stock.

 

Out of the 8 studs/nuts that hold the bumper to the car, my Achieva had only 3 doing any work. Yea, the rear bumper has a sag (harder to tell under the bumper cover).

 

Good Luck!

[Dinsdale]

Thanks......I think I'm heading in that direction now my brain has settled down after a longish grinding session .

 

The original bolts were joined in pairs by a strip of metal and held in place in the holes by push-on clip washers. Some nuts came off okay, others felt the wrath of the grinding disk. I'm considering using standard bolts and welding the heads to the insides of the mounting brackets. Once the car is finished, I'll be giving it an annual once-over for my friend, the owner, so I can run each nut off and back on regularly so they don't seize.

 

I will be adding drain holes at the middle and bottom levels of the reinforcement bar, and these will double as ingress points for squirting in my favourite anti-corrosion agent - used diesel engine oil from the local bus garage. This costs absolutely nothing for ten litres . I use this for any enclosed areas I'm confronted with, and an annual treatment when the car is dry in summer pretty much stops rust starting. The squirting is done with a standard cheapo automotive paint spray gun. I've detached the paint pot from the gun and connected a few feet of rubber pipe to join them back up, allowing me access to places the standard gun setup couldn't manage. An assistant is at times handy to hold the pot for me. Otherwise I hook it up somewhere/somehow to maintain the gravity feed.

[Dinsdale]

Re spraying used diesel engine oil...........

 

I have to use about 40% petrol with the oil to get it through the gun. This means I have to make sure the petrol vapor can evaporate, sometimes by drilling a hole or two (before spraying!) which can be plugged later. I let the car stand for a couple of days and blow some air through the chassis section a few times to help with vapor dispersal.

 

I little time is needed to do this, of course, but it's nothing compared to cutting rusty metal off, fabricating pieces and welding them on .

[Cutlass350]

Good idea about the drain holes.

 

Be careful using old oil as a protectant. Since it can attract and trap dirt/sludge.

Imho, used oil is an old fashion method of rust protection. The POR-15 or undercoating stuff is often much better. Imho, I haven't found anything that compares to POR-15 - that includes the Eastwood stuff. Yes, I properly prepare the items. I even sandblasted the replacement rear axle assembly on my '92 Olds - I used the Eastwood stuff. Imho, the POR-15 stuff that I've done has held up better. Of course, the metal on the rear axle assembly could just suck. Still, POR-15 is now my choice.

 

Note, any metal must be (/should be) properly prepped for POR-15. You can still use POR-15, if the metal is properly prepped. But, if it doesn't last forever, don't go whining on any forums.

 

If you've sprayed it with oil already, it would be hard to properly prep the metal without sandblasting and a good deal of metal prep.

So, just as a future FYI. Try prepping the metal, use POR-15 (in general get the small cans, since you may NOT be able to use a can that was opened before), do it once, and see how it goes.

 

Good Luck!

[Dinsdale]

Hi!

 

Thanks for the POR 15 tip. I checked it out online and there's no supplier here in Poland. A US pint would cost 90 bucks sent from the States!

 

With the oil spray, I use that only in enclosed sections, like inside the bumper bar when it's finished. First I paint the outside metal with Hammerite, available here at 15 bucks or so a litre. I leave it to dry for a couple of days, then spray the oil inside. Harking back to my early days of messing with cars, I frequently noticed the black gunge around the back of engines where they mated to the gearbox. This gunge (oil, sand and general road dust) often reached the engine and gearbox crossmembers and the middle of the firwell (bulkhead in England). There was never any rust in these areas and scraping away the gunge usually revealed pristine, painted metal.

 

There's no oil inside the bumper bar yet, since I start welding it up tomorrow, and hope to have it finished and back on the car by Friday lunchtime.

 

Just a side note......

 

I sent the Regal to guys I know well at the local garage, for what I expected to be some heavy work servicing the terrible-looking brakes, all brown and crusty looking like they'd been stood outdoors in a junk yard for many years. Everything, all round, came off in minutes! The caliper sliders got a clean and greasing, the pistons got a working in and out, and everything's shipshape. Unbelievable.

 

The four rotors got machined flat, and when I asked about the cost I was told (converting to US dollars for you): "A hundred and twenty five dollars, please."

 

Not grumbling with that !

 

They are going to drop the fuel tank tomorrow to replace a couple of severely corroded petrol pipes, then it's a new thermostat, a rear shocker (yet to be ordered but it's available in the US) and the bumper back on, ready to roll.

 

So, all going well. I'm enjoying managing this project for my friend, who is at last getting proper benefit from the money she's spending. This car passed it's annual test a month ago....scandalous!!!!! After the test she was told the car was "fine now".....far from it! Dangerous is the right word.

[cutlasssupremepizza]

$125 to machine 4 rotors? That's a rip in my opinion. Here in the states I can have rotors turned for $12.00 each. I don't know where about your area, but I would not expect 4 rotors to cost over $30 each x 4= 120 dollars.

 

I machined rotors back in auto class, it takes maybe 20-30 minutes a pair.

[Dinsdale]

$125 to machine 4 rotors? That's a rip in my opinion. Here in the states I can have rotors turned for $12.00 each. I don't know where about your area, but I would not expect 4 rotors to cost over $30 each x 4= 120 dollars.

 

I machined rotors back in auto class, it takes maybe 20-30 minutes a pair.

 

The cost of the machining was about $30. The $125 was for everything - for the machining and the labour to strip the brake system down, service it and put it all back together.

 

Sorry for the confusion. I hope you're getting on well with your rebuild.

[Dinsdale]

Got the rear bumper rebuilt, it's back on the car looking like a reinforcement bar . I got a bit lucky I reckon. I'd welded four bolts at the upper mounting points, and the bumper went back on no hassle.

 

Here's a tip if you ever get a welded-on bolt a millimetre or two out of alignment. Grind the thread down on the side until the bolt goes in its hole. The nut will still do its job, if you don't take too much off. This will not be appropriate for ALL situations, but would have helped me with the bumper replacement if a bolt or two (or four ) hadn't wanted to go in.

 

Before and after photos..........must tidy up soon :

Edited November 4, 2014 by Dinsdale

[tornado_735]

Hey, that looks great!

[Luke94vert]

Great job. Looks very nice.

[Crazy K]

very nice! Now come do mine! (just kidding)

 

Since you were thinking of oil coating it, let me suggest: Wax-oil. or even better, homemade wax-oil

http://thelatebay.com/index.php?threads/homemade-waxoyl.33278/

 

I've made it myself with:

1 quart/liter of cheap motor oil or diesel fuel(which is a very thin oil)

1 quart of a solvent kerosene, paint thinner, even gasoline( be careful!)

paraffin canning wax, 1/2 pound. (1/4 kilo)

 

mix all three in an old crock pot, heat until wax is dissolved and all mixed.

 

spray hot mix out of a leaf sprayer into all the places you can in and under your car.

[RobertISaar]

Ken, opinion on using chainsaw bar&chain oil in that brew? some(most?) of them appear to have phosphoric acid in them, which converts iron oxide into iron phosphate, should kill off any existing rust it gets sprayed onto(i don't know what kind of depth it will be effective to, but surface stuff at least).

 

or..... adding phosphoric acid to any oil?

[carkhz316]

Good job on restoring that bumper. It looks great again. For anyone wanting to do preventative rust proofing, when I was at the body shop, we used this http://3mcollision.com/3m-rust-fighter-i-08892.html for doing any internal component/ panel rust proofing after a repair, be it rockers/ quarter panels and the like. It is designed to go anyplace that isn't directly exposed to elements; read: inside common rust points like aforementioned. It dries to a boogery/ wax-like consistency that will hold up better than most any oil spray.