Hello & Future Plans

[rustyboyz]

Hello, I would like to share my progress on my car through a living thread. Starting off, I am only 16, so be nice . I bought my car last year for $500. It is clean on the outside... but not so much underneath. I worked all summer in order to replace the entire front end suspension components and during the school year I am saving to do the rear end.

The car sat for many years before I bought it, however, at first sight I was in love.

My first question is what can I do about a rusty floorpan? There are two MAJOR rust spots that I need to fix ASAP. I want to do it right eventually but for now I think I may rivet some pieces of aluminum? I read about the technique on another forum post.

Thanks for any help.

[Mike W.]

First off, welcome to the group!

Rust is almost impossible to really repair correctly at home, which you may very well know. Riveting in patch panels is certainly something that you can do, less than ideal, but given the hyperexpensive cost of "properly" repairing it, it's a matter of doing what you can, and there are worse techniques. I would try to treat the rust with a rust converter or Por15 or something along with some paint, even basic Rustoleum or the like before riveting on more metal, try to stabilize it some at least. Aluminum? Keep in mind it's weaker so it would have to be thicker than steel, and while it doesn't rust, it still corrodes. Also be aware there are at least 3 different kinds of pop rivets, not even counting diameter, aluminum, steel and stainless steel. Along with standard head and large head.

Good luck with it and keep us posted.

[Panici]

Welcome!
Post some pictures of your project.

Sounds like you're off to a good start. Fixing rust "properly" requires some metal working skills and most certainly a welder.

That said, you can make a "good enough" repair with metal and rivets like you mentioned. At least that method will allow you to go back and fix things permanently in the future if you want to. People also use things like fiberglass mat which is a lot more difficult and messy to remove down the road, and also probably traps more moisture then riveted on panels.

[rustyboyz]

Which type of rivets do you guys recommend? I will probably cut the rust out and apply paint/rust treatment to the areas I cut out. Thank you for all the advice and if all goes well I will attempt to rivet this weekend when ai change the oil. On that note, what oil do you guys run? I use amsoil 15w50.

Also I will post pictures after school today.

[gwb72tii]

16 years old and wrenching on older BMW's. I like you already!

[Panici]

I will probably cut the rust out and apply paint/rust treatment to the areas I cut out. Thank you for all the advice and if all goes well I will attempt to rivet this weekend when ai change the oil. On that note, what oil do you guys run?

Make sure you paint the holes you drill for the rivets to go into. See people skipping this step all the time on YouTube.

I know I used to run conventional 20w50 dino oil in my M20B25, and I bet the M30 of similar vintage and design would like the stuff too. You want something with some ZDDP for the old style camshafts in these.
But that's just my opinion, everyone has their own when it comes to oil. Go down the "bobistheoilguy" website rabbit hole sometime to find out.

[Foonfer]

First of all - hi there. Welcome to the world of awesome cars built before you were born. It's not unlikely that many of your peers perhaps do not know what a manual transmission is, or that something like that even existed. Or a carburetor. I'm envious of you - you are 16, and already have your own car, and it happens to be an amazing car? that's beyond fantastic luck.

Second - Please do not. DO. NOT. use aluminum to patch a body made of steel. Look up "dissimilar metals" and "electrochemical series", which you should be touching on in chemistry class soon (if you haven't already). This means that when you have different metals (aluminum and steel) touching each other for long time, there will be an effect, a reaction between them. I can't remember if it is the "less active" metal (steel) will help oxidize the "more active" metal (Aluminum) quicker, or if it's the other way around - in any case, it is bad news. Stay away from doing that if you can.

Third- There are independent fabricators that make direct weld-on replacement panels for BMW floorboards and other panels which have been proven to be vulnerable to rust. People like https://www.valcasgarage.com/ and others similar to them. They do amazing, under-the-radar work. Be very very careful when approaching rust; the first question should always be "should I repair or let it go", the 2nd should be "how do I go about repairing it" (in my opinion).

[solarinterfere]

Starting a living thread to document your progress on your car project is a great idea! It's impressive that at just 16 years old, you're taking on a project like this and putting in the hard work to learn and restore the vehicle yourself.

drift hunters

[turbodan]

15w50 is a good choice. I used to use VR1 20W50 exclusively but my old stockpile ran out and the price has gone way up. These days I run mobil 1 15w50, it is advertised as suitable for flat tappet applications and contains about 1300ppm ZDDP. It's probably the best choice out there at the moment.

[rustyboyz]

So I had an amazing idea today in physics class (unrelated). It would be a very fun and totally mature thing to lower my car instead of fixing the rust, so that is what I will do. I will poke around the forum to see what I can do to lower it as cheaply as possible. Let me know any tips !

P.S. Ordering parts from Valcas Garage soon. How long that might take to ship?

[rustyboyz]

Thanks for the tips on using dissimilar metals. Will keep in mind. I don't know whether its the stubborn teenager in me or something greater, but I have fo fix this car. It's beyond monetary value.

[Mike W.]

You can repair rust and lower it, many have lowered it with sport springs.

But if you want the absolute cheapest, although not recommenced, you can always cut the springs. Do it a bit at a time if you go that route though, and as long as you're speaking about physics, look up the physics of springs, it's not always what you would expect.

[rustyboyz]

Alright, the rust struck me again. My fuel tank had begun to leak when filled completely until about 7/8 tank. I have to fix this before the floor.

Is there any cheap way AND safe way to fix this?

Does anyone sell replacement tanks that aren't more than $300?

I just can't beat the rust.

[Mike W.]

How bad is it leaking? There are a variety of patching and sealing product that can be used. https://www.amazon.com/POR-15-49208-Gra ... B00B3I2NWG I personally used epoxy on one long ago which helped, but didn't fix it because it was at the seam. E28s are known to leak at the neck sometimes, that might be where yours is leaking. Another possibility is that it isn't the tank at all, but the evap hoses, they're in the neck area and get porous and leak in time. Bit of a pain to replaced on your back with crap falling in your face, but not technically difficult or expensive. You can see where they are in the pic. Radiator shops have also been known to fix leaky tanks, might be worth a few calls.