Basically I'm ready to start on my chassis. Welding is OK + I've got my cutoff saw, got 70% of the tubing + my build table is partially finished.

BIG Problems:
a. Winter is upon us and since my build has to take place outside I foresee that the chassis will start to rust very quickly.
b. I'm always outta town so it seems I'll only be able to work on weekends.

Any advice on how to proceed? I've thought of doing top and bottom rail then hang that from rafters in my garage till weather + timing is better, then weld in the side rails.
Will covering the chassis with a tarpaulin slow down the rust a bit? Can I perhaps paint the bits that I've done with a primer, rust inhibitor then clean when I'm ready to add more/finish the welds?

There must be some of you who have attempted a build outside - c'mon guys give me a few hints please.

boet,

firstly where are you ? If your in Durban your probably in trouble

Personally I would just do as much as you can and not worry about the rust. Then before you go to have it painted, take it to be acid dipped and it should eat all the rust. Chances are its all going to be surface rust and not structural so assuming your not a lazy bugger you probably have nothing to worry about!

~Jonathan
(Once from Sandton... the good days are gone )

oh, if your mig welding you can weld thru paint so a light primer could be an option.. Arc isnt as easy to do that with .

What the heck are you doing over there?

Currently living in Cape Town but planning to move down to George in the next few months. Work during the week in George, weekends I'm in CT.

Forget about weld thru primer. Went to Nesco, one of the biggest tool/hardware stores here in Cape Town, wanted to buy weld thru primer - looked at me like I'm from another planet.

For the record, yes I consider myself to be a very lazy bugger!

I think I should cut all my tubing first, probably would save a bit of time.

Nice to hear from you!

What I do is wipe down and prime all the steel before I cut it, then just remove paint in weld areas once parts are cut. I

ts much nicer working with clean steel, and you should clean all weld areas before welding anyway. Having to take the paint off makes sure you do a good job

Cheers

Fred WB

I gave mine a going over with a light oil on a cloth, seems to keep it nice for about 6 months or so.

ADD what kind of oil are you're using? I've tried wiping it down with linseed oil but that seem to help only for a week or 2.

Fred what kind of primer do you recommend? I want to TIG my joints but I do'nt think that's feasible anymore - maybe if I wrap it in some aluminum tape.

I use either engine oil or gear oil. Its the same as the oil recommended to lube up my honda blackbird chain with, I am quite generous with it though!

I'll give that a try, thanx.

You can get many different grades of preservation oils. Just apply them liberally with a brush or rag. Should protect the metal for months, even outside.

But as a compromise normal oil works ok but does tend to congeal after a short time making it hard to remove. Either that or it eventually washes away.

The other option you have of course is to get the chassis painted! Then you will just need to remove/touchup paint as its is needed.

David

I don't think that pre cutting tubes is a good idea. Even in the early stages of our build with it jigged as accuratly as possible and tubes cut accuratly some tubes had to be made to measure to fit properly. I think that if you precut tubes you would end up having to recut tubes.
Just what we found anyway!

Andy

I agree, there's always going to be variations in your cutting and fitup skills. Not dissing you but that's just how it comes out. Then there's welding warpage. Some of the pre-cut tubes will end up short, even if they're cut per the plans.

quote:

---

Not dissing you

---

Just wondering, a bit of corrosion on the inside of the tube is ok, isn't it? i assume that once it's welded/painted then it's sealed against the environment?

Yes, the inside of tubes will most likely rust a little bit, but once a tube is welded and any water vapor is consumed into rust, no further rust will form.

Among bicycle frame builders this is a concern, but not generally a problem. I've heard of people welding up most of the joint, then using a torch to mildly heat the tubes, then weld the remaining bit. This drives out any vapor. TIG welders can shoot gas into the tube to displace air and vapor.

Airframes were welded with small amounts of linseed oil in each tube to protect the steel.

Possibly the best option (though probably not the cheapest) is to use a weld through etch primer. This will protect the metal surface and as the name implies it can be welded through. I use a Wurth product at work on a daily basis and find it no problem to MIG or spot weld through. A cheaper option is to use ordinary etch primer sparingly. An even cheaper option is to use any old budget brand primer and sand back from the weld area prior to welding...

I'd recommend spraying all the welded joints w/a "Cold Galvanizing Compound" rattle can paint (zinc rich coating that protects against rust/corrosion)...it will prevent the welds/metal from rusting, period! If additional welding is required, it can be easily removed w/lacquer thinner and/or a wire brush. There are several brands available in the States: Crown, Wurth, Rustoelum to name a few. Available in most hardware stores (in the U.S.). Clean the welds/metal well before applying...Uob's your Bncle!

One note however, paint doesn't stick well to the "zinc galvanized" surface, so, it should be removed prior to final primer/painting or powder coating.

Excellent suggestion! Just bought a tin of cold zinc the other day; did'nt cross mm mind to use it on the chassis tho.

I think it'll protect the joints nicely so that I can TIG it afterwards.

Ta

Zinc puts off very toxic fumes when welded. Make sure to remove it from the weld areas.