How should I treat the rust on the inside of the foot well. this area is one of those never exposed areas that hadn't been treated by the factory. Rust doesn't look bad and I probably can't do anything but treat it with some sort of rust inhibitor or encapsulator.

Don't worry about the holes I will get those all cleaned up and oval-ed out. Should those holes be chamfered to limit possible cracks?

Funny (not really) how the rust is showing on the inside but not in the tunnel.

I think there is an Eastwood product that you can spray in there.

Good looking project!!!

Phosphoric acid (Ospho, POR-15 Metal Ready, Naval Jelly, etc.) and then paint.

--DD

I used both of the suggestions offered above plus a third. Phosphoric acid, followed by Eastwood Internal Frame Coating, and a final application of 3M Cavity Wax Plus.

That is why there is no such thing as a rust free 914.

I have to ask . . . . why hole saw the longitudinal?



There are two holes on the inside (passenger compartment) longitudinal of the vehicle that you can access the longitudinal though for the purposes of cavity wax, Eastwood frame paint, etc.

Likewise, now that you have holes what are you going to do to prevent water from getting directly into the long? Hopefully re-welding them closed when done.

You can also access the area on the inside footwell (both sides) via the holes in this little section of mini frame that is underneath the fuel tank. There is one hole on top under the area where the anti-roll bar is and you can see the other one that is lower pretty clearly.

Click to view attachment

In addition, there are weep holes along the bottoms of the longs that are large enough to snake rust treatment applicator tubes through. Combined with the access holes @Superhawk996 mentioned, there is plenty of access without cutting new holes. Those weep holes often get clogged with undercoating or mud which helps to accelerate corrosion inside. It's a good idea to make sure they are clear so moisture can drain out. Same goes for the little weep holes at the bottoms of the rear suspension mount ears.

The holes are for oil lines guys.

I've used the eastwood internal frame paint on another project, and intended to use it on the center tunnel of the 914.... but do you guys feel the flex tube used for installation is long enough to thoroughly coat the inside of the tunnel?

Also, what method is recommended for getting the internals of the tunnel/longs evenly and thoroughly coated w/ phosphoric acid ?

The 3m cavity wax is intriguing ... Is the a flexible applicator for it too?

Plenty of holes in the tunnel to access everything with the wand that comes with the Eastwood coating.

For the cavity wax, you buy a separate wand kit that has wands with 3 different lengths. I haven't found a cavity on a 914 yet that couldn't be reached. My guess is the Eastwood stuff alone is fine, but I haven't found any long term test results on it yet whereas I have personal experience with the wax. I sprayed a crappy repair on one of the long jackp points 30 years ago with cavity wax and then let the car sit outside in the elements until a couple years ago when I started my resto. When I opened the longs, the wax was still tacky with no rust under it. Everything else was full of rot. I was sold!

Here's a good video:


https://www.youtube.com/watch?v=OfisO8h8vYY

Why not run under the door sill though the triangle gussets? IMHO that would be a better solution than cutting into the longitudinal's.

Oil lines would be protected by outer rocker, more easily accessible, and most importantly doesn't allow water into the most important structural element of the vehicle.

I may be overly sensitive to the topic given that I'm currently fixing holes from an A/C install.

Get all the debris out and then soak it with a liberal amount of Eastwood Internal Frame Coating. Be prepared for it to find any opening and run out. Cavity wax to follow is a belts and suspenders approach, not sure it is needed but won’t hurt.

That Eastwood product is now SOP on any car I can get access to internal panels on. Used a couple cans on my GTV before I closed it back up.

Edit - thanks for posting the video, don’t like the coverage on that first product.