1. Matthew Byrom

    Matthew Byrom Newbie

    Evening all,

    Time has come to sort out the old Trabant in earnest & there are a couple of holes in the engine bay that need sorting. One near the battery & one near to the left suspension. All on the front-left wheel-arch, basically. Small-ish but enough to warrant a decent patch.

    I've been learning to weld & doing OK with a MIG, according to my mate, but I'd like to ask those that do weld their Trabants, what thickness of sheet steel should I be buying in order to fabricate my own patches?

    The steel itself seems really thin, I mean less than 3mm, but I don't have a micrometer to be able to gauge the thickness accurately.

    Any advice would be appreciated.
    RogerDerSchrauber likes this.
  2. RogerDerSchrauber

    RogerDerSchrauber Premium Member Forum Donor

    As somebody who has done too much body work / rust removal in his life, and hopes he never has to again, rout it ALL out. Check it all. You don't want to have to go back, since will be be doubly worse next time. You may discover the wheel boxes need a lot more work than you think. When the wheel boxes are in need of repair, almost always the sills under the doors are, too. Check the trunk and the rear inner fender areas, too. The Trabant steel isn't of the best quality, (not sure of the exact thickness) but, good news, you can order all these replacement parts to weld in: sills, wheelboxes, floors, etc.
    Last edited: Feb 18, 2018
    Matthew Byrom likes this.
  3. Matthew Byrom

    Matthew Byrom Newbie

    Thanks for the advice. I see Trabantwelt offer replacement bits. From what you say I'm probably better off getting a full front left wheel arch just in case if the small hole becomes huge after cleaning. I'll be checking over all the body as I go.
    RogerDerSchrauber likes this.
  4. mbeamish

    mbeamish Loyal Comrade

    I would use 0.8mm steel ,1mm would do also but harder to shape and bend
    Matthew Byrom likes this.
  5. Matthew Byrom

    Matthew Byrom Newbie

    Thank you. Is it really just 0.8mm?

    I've been learning to stitch 3mm. More practice on thinner metal I think, then after Easter I'm buying my own welder.
  6. kev the builder

    kev the builder Loyal Comrade

    Yes it's 0.8mm or 18 gauge in old money it's easy to blow holes in so good clean metals needed to weld to
    Matthew Byrom likes this.
  7. 'bant

    'bant Loyal Comrade

    If you are using MIG then you can reduce the chance of blowing holes by using thinner wire, turn the gas flow up a bit and use the lowest power setting your MIG set has. Don't try to lay down a long run of weld, do spots a centimetre apart and then go back and add more spots to close up the gaps (if you need a seam weld). It is all too easy when trying to weld a seam in one go melt a centimetre long hole in your car as, in trying to get a decent weld you move the tip too slowly. Move it too quickly and you won't make a good weld either but at least is easier to correct your mistake.

    If you want an easy MIG life invest in a decent quality welding set with a separate gas bottle and get a proper big bottle with a regulator. I have done a small amount of gasless MIG welding and it is much harder and slower. You cannot go back and re-weld a dodgy spot without first removing the slag from the top of the previous weld.
  8. Matthew Byrom

    Matthew Byrom Newbie

    Thanks for the advice. Going to opt for a gas mig and have been getting good at spot welds. Building up afterwards seems the most reliable way for me to stitch metal together without blowing holes in .8mm.

    It's in the engine bay so I'm not fussed about pretty, just want it solid. Going to take the precaution of removing fuel tank etc.

    Going to start prepping this weekend ahead of welder turning up. Taken lots of photos to remind me where everything goes back. :)
  9. 'bant

    'bant Loyal Comrade

    Before I forget, remember to sand down the weld after you have finished. If the welds are good you should be able to take them back to (almost) the level of the surrounding metal. This is important as big blobs of weld weaken the structure. You get a big stress concentration in the corner where the blob meets the sheet metal. As this is also where the heat affected zone starts (which is weaker and more prone to corrosion than the weld or the rest of the bodywork) then it is a good idea to flatten the welds.

    I use angle grinder fibre sanding discs like these that need a plastic backing plate. It is much easier to sand carefully with these than with a solid grinding disc as the angle grinder bounces around less (makes a lot less noise too). 80 grit is coarse enough to flatten welds quickly 120 if you are worried about damaging the surrounding bodywork.

    If you have bought an angle grinder then go and get a spare set of motor brushes and tape them to the tool box. Especially if it is a no-name brand angle grinder. Invariably motor brushes wear out just as you are in the middle of a big rush job when the shops have shut o_O
  10. mati0921

    mati0921 Loyal Comrade

    +1 on the spare parts for angle grinder. :)
    I bought a cheap one that said 5 year warranty on the box. now i am on the third one and it is starting to make funny noises sometimes. this is within one year. :)
    They said that when i change it for a new one the warranty starts over at 5 years, so i will have free angle grinders forever. :)
  11. kev the builder

    kev the builder Loyal Comrade

    wow free angle grinders for life sounds good to me
  12. Andrewwoey

    Andrewwoey Loyal Comrade

    That sounds like a great warranty.
  13. Matthew Byrom

    Matthew Byrom Newbie

    Good tip on the sanding! I was going to leave the welds on the mistaken understanding that it might make the join stronger to leave more metal.

    Point taken & will sand those blobs - Because blobs there will be...

    I have 2 old grinders to hand. No biggie if they burn out. I don't have an awful lot to weld, to be fair. It's just in awkward places.

    I'll take pics as I go as an aid to my memory if anything else...
  14. 'bant

    'bant Loyal Comrade

    You are not the first to have that idea and won't be the last :D I remember maybe 20 years ago that there was a feature in one of the IK MINI magazines about a company producing cabriolet Minis. The company boss stated that they welded the inside of the rear vertical seam in the boot and left the big blobs of weld there to "make it stronger" before covering up the blob covered seam with another plate. While I didn't get round to writing to a letter to point out that this was not a good idea, someone else did and their letter was published in the following edition of the magazine. I do wonder if any of their conversions are still running around with those extra strong welds...

    One other thing you might find useful is to fill an old washing up liquid bottle with water. It makes for a cheap and very easy to use fire extinguisher for putting out small fires for things like blobs of underseal, wax rust protection in box sections or old seam sealer that you didn't notice before you started welding. You can get that jet of water exactly where you need it.
  15. Matthew Byrom

    Matthew Byrom Newbie

    Oh that's a cracking tip on the washing up bottle! I have a fire extinguisher handy but if I can avoid using it for daft things, then great.

    Right, equipment all set. Just taken front wings off - Okaaaaay... Bit more corrosion than I thought, but as I expected. Wasn't helped by a previous owner using a dash of expanding foam to plug a gap or two on the edge of the wheel arches! :D
  16. kev the builder

    kev the builder Loyal Comrade

    There always more rust once you start its like an iceberg and as you clean the rust and paint ready to weld the holes grow especialy if you use an angle grinder mounted wire wheel as theyre aggressive but you want good steel to weld to
  17. Andrewwoey

    Andrewwoey Loyal Comrade

    I hate welding old cars. Its always a game chasing holes. Its a good test for your patience :mad:

  18. kev the builder

    kev the builder Loyal Comrade

    yes you start in one place and end up somewhere else,its not that easy welding upside down laid under the car when you dont have a car lift
  19. 'bant

    'bant Loyal Comrade

    It's bad enough under a VW bus where you can at least crawl in one side and out the other. With the Trabant being low to the ground you have to come back out the way you came and crawl back under the other side if you are working on a spot near the middle of the car. Then you get yourself into position only to realise that you should have moved the welder round to the other side of the car as well...
    Matthew Byrom likes this.
  20. 'bant

    'bant Loyal Comrade

    We want to see the pictures! :D
    Matthew Byrom likes this.

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