The previous owner had the frame coated but I've found inside the rails, it's rusting from the inside out! Especially in the cross member by the gas tank.

Is there anything I could / should do or just wait until the inevitable?

 

Is there holes in it, or did you just feel rust inside, if the latter don't worry about it

 

I'll check again but it looks like small chunks of metal can be scraped off with a screwdriver!

Is there somthing I should shoot or spray into the frame?

 

All C3 frames have rust in them unless they are brand new, it is just a matter of time before they all go back to nature

Post some pics if you can and we will tell you if it is time to worry about it

 

Ive been thinking about taking a long 1/4 air line used for air brakes rigging up a spray nozzle that spreads wide on the end shoving it down the full length of my frame using por -15 diluted a bit ofcoarse then slowly pulling it through the frame the only thing is id half to use a little tri pod or something on the end so it covers the inside evenly.can it be done? well who says it cant be and ill give it a whirl.

 

You will find there are reinforcement baffles inside the frame rails that will prevent straight through access. There is one behind the side pipe slot on both sides, but there may be more forward. Straighten a coat hanger and poke it back there and it won't go far. I coated the inside of my frame with Z-Bart type undercoating using a modified engine cleaning sprayer from Harbor Freight. To do this, I removed the frame body mounts and used the open holes for sprayer access.

 

thanks for the info guess it will kinda work

 

After you check it out & it's ok, spray some undercoating in the rails.
http://www.mgocaccessories.co.uk/aca...axoyl_171.html

 

Waxoil is great stuff for rustproofing the inside of the chassis, its been around in the UK for years and used to great effect. Just had my chassis done with it during the rebuild, it will never rust again!

www.graemeinglis.com

 

When you go to jack your car up with the jack under the frame and the jack starts sinking in , you know you have problems. I just took my 80 off the road . It will be many years before its driven again. The frame on both sides in back of the doors is almost all gone .

 

Yeah I'd say that frame is shot

 

 

The frame has pockets that are not manually accessable... only a fluid (such as saltwater) or gas can get into them. As indicated above... you need to be creative to spray anything into them. The pocketed areas are also the most critical in terms of frame integrity. On a badly rusted frame, when you tap it with a hammer, large chunks of rust will fracture off. When your frame gets to this point, you're both in trouble. They absolutely do rust from the inside out.... and when you see a rust perforation from the outside, the inside is nearly gone.

Light scaling rust is common even on a southern car. But chunks are the kiss of death.

You can buy sections of frame to repair this (body off), and in some cases a whole frame is available from aftermarket vendors.

I have first hand experience with frame rust.... my first three cars went to the crusher due to frame rot.... 1959 Ford, 1958 T'Bird, and 1966 Ford "Custom" NY State Police Car.

My C2 needs some frame repair.... a victim of the Binghamton NY/Scranton PA salt bath.

 

Just be extremely careful if you spray POR-15. It will damage your lungs if you inhale it. If you want a quick (and dirty) method, just spray used motor oil inside the frame rails. You can repeat the process a couple of times a year if needed. Ever notice how well preserved the metal pieces are under a chronically leaking area of the engine? One of my front control arms was dry and rusty, and the other one had a 3/16" layer of oil and dirt covering it. Underneath the crud the arm looked like it just came from the factory.

Rick B.

 

I'll say....Passenger side control arms looked brand new after scraping years of old motor oil and crap off!

 

The removable differential crossmember... I removed mine and cleaned out the interior as best I could. Next I took duct tape and sealed all of the holes on the crossmember except one of the top access holes for the differential bolts. I then poured in about a pint + of Rustoleum primer. Then I duct taped shut the one remaining hole. Next I rotated and sloshed all of the primer until it must have completley coated the interior. I removed all the duct tape and poured out all of the Rustoleum and waited for the interior coating to dry. Took a couple of days.

 

I was curious about Waxoyl, so I did a Goggle search and came up with the following posted on a Miata Forum. I have no idea if this works, just passing on what I have found.

How to make your own Waxoyl:

It's pretty simple, really. Take a pound or so of parafin wax and grind
it up with a cheese grater. Soak it in a half gallon of mineral spirits
until all of the wax is dissolved. This might require allowing it to
sit in a closed container for a couple of weeks. Stirring will cause
most of the wax to dissolve, but soaking should take care of the rest.
Generally try to dissolve as much wax as the mineral spirits will hold.

After that, dump in a couple of pints of mineral oil ( less of a smell )
or non-detergent motor oil.

If the mixture is thick, thin it further with more mineral spirits until
it is of a sprayable consistency.

Buy one of those cheap engine sprayers at the local auto or tool store
that carrys air tools. It is a metal wand with an air fitting, a spray
button and a rubber tube to dip in whatever you are spraying. Rent or
borrow an air compressor.

Safely elevate your car so that you can get at the underside. Spray the
solution onto, and into every crevice, crack, hole, and surface you can
get to. Then let the excess drip off. The beauty of it is that the stuff
will soak into any rust spots. The rust seems to hold it like a sponge.
It will also bleed into the smallest cracks and folds of the body and
protect there, too.

All you need to do is repeat this every year, and rusting should be
greatly reduced.