Modern Vespa

If you are really worried about any pitting try using a sanding wheel with the Dremel and just give it a light cleanup. But it doesn't look bad. Mine is also worse.

Seen worse and ran worse.

Agree with Chandlerman. Lap and go.

The rust doesn't look bad at all, especially as you were able to get it down to bright metal. It's not unusual to find light rust between overlapping spot welded assemblies. You would find that even in sound parts of the metal. It looks like you stopped in a good place. Knowing where to stop is a really good thing.

Thanks for the responses!

To lap the cylinder head – I would turn it? Maybe on a flat surface on 600 (or higher?) grit sandpaper? Like lapping valves?

The metal looks not bad! There is some surface rust between the sheets of metal going back further, but it's very light. I was thinking I would just remove the areas where the rust was expanding between the metal.

The bike was outside for decades, and the seat wore away. I think the areas with the worst rust was from water getting in to the air intake under the seat, and seeping down. And worst where it was more horizontal. Just the areas I cut out.

If I leave the areas that haven't expanded, are they pretty safe from continuing to rust?

One more.

Is this a decent cylinder kit?

I had wanted to use an original Piaggio 200 one, but they're out of stock at Scooterwest. But this one is available.

Coming along. Slowly.

Still thinking about color.

The floorboard.

The scale goes up far. But the rust isn't that bad. There's a lot of volume, but it hasn't eaten away so much of the frame.

Almost ready to blast. And I think I might take to a welding shop. I got a recommendation.

Welding sounds fun, but I'm not confident I'd do a good job my first time.

I cant comment to on going higher... would be good to treat as much of that rust as you can, but I'd be worried about running out of real estate.

Your documenting of this has been super impressive! Keep it up and thanks.

It looks fine. Keep going. Hiring a person to weld is cool. I even have a welder, and I'm too damn lazy to get everything out to do stuff.

The Apocalypse is upon us, so get it going and cruise it down the highway as long as you can. I'm riding all my bikes much more. I think they love me much more now too, gash darn it.

Thanks!

I'm regretting not getting the Grabor one. Considering it, but it takes weeks to arrive. I chose this shorter one, bc it was smaller to ship, and had the struts.

But it's the whole thing, so can go higher.

The bike must have been submerged in water a some point? How does that rust form?

Welding. Hard.

I got the materials to weld, and did a test with stitch and plug welds.

It's really hard! I didn't take enough photos.

I think I'll take to a welder, but I hope they do an ok job. I can drill all the holes for the plug welds.

Learn something new each day.

I guess I need these for the seam. If the metal is too close, it expands and warps, and you need a bit of space to fill in with the weld.

Still on the fence about trying this. I will practice a day or two more.

This project is taking forever.

You're going at 'em too hard. Just do little baby tacks here and there until it's filled up.

I posted this video on another thread. If you have 40 min to kill you'll get a lot better idea of what that thin sheet metal takes:

Thanks! I watched when you posted. I'll watch again!

These didn't turn out bad for a first attempt! But still need practice. I had a welding lesson, but from someone who does heavy duty welding.

I used .023 wire, and the lowest heat and feed setting

You need to turn up the heat on your machine. I use one setting higher than the lowest for sheet metal. Otherwise you don't get good penetration and the bead is too high.

When I butt weld, I do a few tacks at a time and space them out to disperse the heat. Grind down the racks, doesn't have to be completely flat, straighten the seam and add more takes. Repeat. After finish grinding, I shine a light from the other side to find voids and pinholes. Mark them with a sharply so you can see them and weld them up. Those clamps are ok. Sometimes I will even duct tape a panel in place just to get it started. If you can, clamp a piece of copper behind your seam. The weld won't stick to copper so you can fill big voids that way. Get a piece of copper pipe and hammer it flat.

Looks like my first attempts!
Try raising the feed bit by bit on your practice setups.

Thanks for the tips! I'll try again this week.

I might do the welds before blasting it. But would need to really clean out the inside of the frame.

Is it ok to leave the metal bare between the panels? After seeing all the rust that built up.

But water had gotten inside the frame. I definitely want to seam seal along the floorboard.

I use a zinc weld through primer in the places where panels overlap. If it is a large section, I will paint the inside of the panel with something like rustoleum, but use the weld through on the edges where I weld. You could also just do the whole inner side with the weld through. It's also called cold galv etc. You can get it at welding supply stores. Seam sealing is a good idea. You could also etch the metal with something like Ospho before the weld through. I doubt the rust would return.

This guy uses an alternate approach to butt welding sheet metal that seems pretty slick. The sheet metal clamps made me think of it.

That's a neat trick. I gotta try that.

Genius!
This should be a Wiki at your welding thread.

Fun fact:
Only a welder can tell his significant other that he's going to the shop to "grind out my butt welds" in a serious manner.

This is great! Thanks!

That 45 degree overlay cut cleans all the gaps. It's genius.

That technique is really interesting. It might work for the bridge piece. Those clamps on't fit in there unliess it's cut up higher above the frame.

He put the door in upside down on that video. It hinges open into the wind.

It's correct. It's on the left-hand side, behind the cab.

Oh. I thought that was the right side.

Spot welds.

With the floorboard off, I can reach the spot welds here with an actual spot welder.

I was looking at photos. It looks like my old p200 has a LOT more spot welds than a rally frame photo I found.

Is that right?

The P looks like it has about 20 on the side of the bridge, then two rows of three on the top.

This rally frame seems to have less.

I guess I'll follow the P.

I went back and checked after you posted that, because I was pretty sure it was by the driver's door. It's not obvious with the bed off the truck, though.

I have a similar spot welder from Harbor Freight. It's ok for thin stuff but not sure if it would work on the thicker metal of the tunnel. I bought it to use on my bus and ended up doing plug welds anyway. I seemed to have the best luck by turning up my welder and welding right through the first layer rather than drilling a hole. Practice on the bench both ways until you can bang out a row.

If you look at your photos you can see that the spot welds were made with much bigger tongs. The HF units make much smaller spot welds.
Unfortunately plug welds will not look factory as it won't make a dimple, but it will still be plenty strong.

I think I might end up with plug welds. I love the dimples, though. I might try to mimic them.

Last little cleanup. And surgery is done. Ready for blasting.

Lesson: Don't leave your vespa out in the rain. And definitely not for outside for 35 years.

That pitting is really deep. I would be tempted to cut out that little angle piece and weld a new piece in.

You could also blast it clean, back up with copper and fill up the pits. I figured out a way to weld up pits by increasing the wire stick out and decreasing the angle of the torch... like less than 45* and zig zagging the torch back and forth. This makes a cold non penetrating weld that just puts a layer of weld material over the pits. Worst case scenario, it doesn't work and you patch it.

It's pretty bad!

I didn't even see it before. The rust in places is very condensed and solid, and doesn't come off easily.

When I blast it, it might reveal more.

With these, it seems possible to build them up with the welder, since they are inside. There are only a couple of places it has worn through, and very small holes. But blasting might reveal a lot.

This project is a pain! My last rusty vespa repair.

It's a shame it's not a PX. You can still buy whole frames NOS for those.

All collected for blasting, and powder coating.

Labored decision on the powder coating, but it's really the best thing for the steel rims. There's enough paint on the inside of the brake cover to match. Matte silver. Matte black (almost. very dark gray) fender crest and front spring.

That is some fine, fine booty!

I love it. I think the SS was just slightly wider, but those two have the best shape.

Definitely has the wasp vibe too.

Tiresss. Tire-ed.

I was looking at tires. I love Continental Zippy 1s, even though they aren't really the style of a stock Rally. The rounded sport tires just handle so well.

It looks like Zippy 1s might be discontinued. You can still find them in the US, but the German shops don't have them.

It looks like they've been replaced with one called Conti Twist.

I have these clamps (Unused so far, let me know if you want to borrow - I am happy to send your way for as long as you need them!

Thanks!! I ended up getting some. One of those things I'll use once.

I hope I don't have to do the same with a 220v spot welder. Those are such specialized thing, they don't seem to be at equipment rental places.