Goggomobiles welding floor panels

[Goggomobile]

Hi all

im 6m into restoring 3 Goggomobiles ...Ground up. I'm a novice fur sure ...

If I work out the best way on first one the next 2 will be easier ..I'm thinking...

ive stripped the chassis and have to replace the floor pans. The rest is in good nic as it has been housed under cover. The original chassis was mostly spot welded .... Looking for advice on best way to weld it ... I'll probably get it sand blaster before welding ...

i have a MIG and a inverter arc ... I have gas less wire .... I'm thinking of getting gas but Not sure of the best gas or system... I read about drilling holes and doing my own spot welds ... Less heat ...

should i I over lap the joints or butt ?

or or should I silver solder ...


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Randal

[Karl Robbers]

If I were setting up the mig purely for bodywork, I would say .6mm wire with either straight CO2 or something like argoshield 40 or the air liquide equivalent which is aimed at the smash repair industry. The argoshield gas is probably a bit better for a novice on thin material, although CO2 will shine if the panels are a bit dirty or if rust is encountered.
You can buy an air operated punch and flange tool that will set up beautiful lap joints that finish flush but you must use a weld through primer between your laps and then preferably seal the joint from behind for best longevity. They will be easier to weld than butt joints obviously.
As far as sandblasting the shell, brilliant idea, provided you can find a blaster who will not go too hard on the panels and either wear through them or distort them. Stay away from soda blasting. While soda blasting is promoted to the car restorer, it has a very nasty habit of leaching out of any seams once exposed to moisture and then forming an acid that will blister and lift your paint. I was involved in the restoration of a 1967 Mustang, (the Rustang we christened it), and the top quality panelbeater/spraypainter enlisted to apply the final touches would only do so on the proviso that the shell was not soda blasted. We had it blasted with garnet and the operator did a marvellous job. No distortion and no excessive thinning of panels.
This will test your mig out. Any mig can weld at high power, but the low end of the range separates the quality machines from the also rans.

[Michael G]

Not wishing to be a wet blanket, but it may be worth finding out whether there are any legal requirements for this work - ie has to be done by a qualified welder or to a particular standard. I've heard stories of people doing beautiful work but then not being able to have vehicles registered because the work was not certified. (That was a race chassis, but it may be similar)

Michael

[Goggomobile]

Michael and Karl

many thanks ... Many questions answered and many raised ..all good .

I just received new re manufactured rear pans from Germany .. Can you believe they still have the dies after 65 years ... Still having trouble getting front pans .. Clearly not doing a run until they get enough orders ...

ok .. Argoshield 40 .. Ta .. I didn't have a clue on gases .. Now I'm a Google expert ..

I have a Lincoln Electric MIG Welder180C with manually adjustable voltage and speed .. Is this a good one for small welds ?

punch / flange tool .. Ta ... Never heard of such a thing ... Found one online ..I had brought this tough tittle spot weld remover ... Kind of like a mini hole saw drill but 5-6 mm .. Was going to take ages to cut holes .. Punch will do it in no time .

Approvals ... Mm never thought of that .. I'm in Qld ... I will talk to Dept of Registration And the Goggomobile Guys up this way .. Lucky most of the chassis is in great Nic ...

Bead blasting - this looked attractive but will avoid ... Sand blasters on the Gold Coast are a rarity now days .. Will check out Brisbane


Randal

[soundman]

There is no requirement for qualifications or certifacation when doing panel work.

Even doing chassis repairs is a grey area.

It is a wise thing t make sure your welds are good.......so practice and testing with a hammer will be a requirement.


Oh on the subject of sand blasting the floor pan.

Sand blasing is a wonderfully thorough process.....but it is slow and expensive on thin material.
If you are not affraid of some work.......a combination of thngs like a scraper, a grnder with a wire brush and a grinder with a flap wheel with get most of it done faster and cheaper.

I have sand blasted the inside of a 16 foot aluminium boat with a small hand sand blaster...and it is doable....but use the more efficient methods to remove the bulk of the material.

cheers

[KBs PensNmore]

Goggomobile.
Welcome to the forum, you'll find a lot of useful information here. At the bottom of the forums listing, on the left hand side, TKO is trying to get a Restoration Forum going, you might like to put your project on there, for other restorers to see and comment with advise.
You'll find the flange tool will be of great help, as it will give you a lip to weld to, instead of trying to butt weld it. Biggest problem with butt welds on thin material is for the weld to burn through, creating holes. Before you start to weld, practice with the welder, to get the best setting and welds, using a similar thickness metal as the chassis. Take photos of the welds and repairs before painting, particularly in critical areas, suspension points for example, as these will help IF there should be a problem.
If having to grind welds, grind across them, as if going along the welds, it can cause cracking. 80 Grit sanding discs are better for this type of work, same thing applies though, re cracking.
Regards
Kryn

[China]

The question of but joints or lap joints will be determined by how it was done on the original, if you are
doing a restoration it needs to be identical, if you are only doing a recondition/repair then that is a different matter

[Simplicity]

I would not recommend sand blasting at all.
The problem with sand blasting is it work hardens the metal.
This then becomes a Bigger problem when you try to panel beat it.
Leave sand blasting for thicker metal projects like machine tools.
There are other more suitable ways
One is plastic medium blasting or crushed walnut shel I think.
They both remove paint tar and stuff
But don't harden the metal in any way.
With panel beading when I was panel beating any panel that we needed to work with after welding with a hammer was only ever welded with gas oxy.
Mig welds are hard to hammer flat or work with if u need to.
They tend to tear and you end up making a big mess.
I know gas welding can be hard to learn
But it is the best way in my opinion to weld body panels especially if your doing rust and body repairs note point tig welding was new when I was learning so we never used it
So I cant comment on tig welding.
Can't wait to see some more pics

[soundman]

I think it all comes down to what is appropriate for the situation.

Gas welding seems to have some prodigeous advantages in rust repair and panel work generally....yes I have done a little and with gas.
The processes of welding, heating & beating are well proven, praciticed and established.

But it was the MIG that braught the "cut and shut" to a new level because of its ability to weld fairly thin metal with maximum speed and minimum distortion......problem is the metal needs to be pretty clean.

The thing is with MIG, you can join two pieces of panel that are the right shape and not have to beat on them very much at all.
If all goes well, grind the visable welds flush and in with the bog.


AS I mentioned earlier.....I don't believe sand blasting whole bodies or even whole floor pans from their raw painted and dirty state is necessarily clever or efficient.

But I think sand blasting most definitely has a place.

remember there is a very big difference between heavy, high intensity, high pressure sand blasting, and blasting at lower intensity.
And most definitely there are other choices of media available these days.

Let me tell you there is nothing like sand blasting for getting into difficult places and cleaning up crevices, textured or shaped parts.

And ya realy cant go past sand blasting for generating a good key to promote paint adhesion.

What effect the blasting has on the surface metal can vary greatly on the material and equipment used and the intensity of the blasting.

I knew a bloke who took a roller door to work and got the blokes in the bast room to have a go at it......well it distorted so much it took 6 blokes to man handle it into the scrap skip.

If ya want to get material off fast, ya can't go past heavy garnet grit......but glass bead gives a much smoother finish and is less agressive generally.

I have not used walnut or macadamia shell, crushed glass, the modern plastic gritts or soda.

But they all have their place......I might get a chance at some of these soon.

I have seen small scale sand blasting used very sucessfully in rust repair. There are situations where it is very good at removing rusty material and leaving sound clean metal behind.

IF I and my mates had access to sand blasting back in the 80's, a lot of our rust repairs would have been easier and more sucessfull......but back then we borrowed or hired compressors and spray guns...because they where expensive..unlike now.


Using sand blasting can avoid having the remove much larger sections by some sort of mechanical cutting.

In many situations, sand blasting can thoroughly remove the rust allowing something other that cutting and welding to be used to repair the rust..... fill welding, brazing, lead wiping or bogging being a viable and permanent solution.

A mate replaced the rear footwells on one of his cars.....most of the section was cut out using a grinder......but a couple of the lips came away reasonably well........it was sand blasting these lips and the edges of the repair that made the job so much easier, faster and cleaner.......and more durable.

If he'd not have sand blasted these lips....they probably would have needed cutting away and further reconstruction.





As far as a rust repair being original in a restoration......Oh seroulsy.

It is simply not possible to replicate the methods used in assembly of the original vehicle.....even if you could get a premade or recovered section of panel.

Most of the repair sections do not join in the same places as the original panels, so it is a case of making the repair as clean and tradesman like as possible....and above all structrually sound.

cheers

[China]

If you want to do a first class restoration find a company that can does "chemical dipping" I have done this with all the vehicles that I have restored, removes nothing but surface coatings and does not distort the panels, and is given s light rust resistant coating this allowes the restorer to identify what does or dose not need attension

[Karl Robbers]

If you want to do a first class restoration find a company that can does "chemical dipping" I have done this with all the vehicles that I have restored, removes nothing but surface coatings and does not distort the panels, and is given s light rust resistant coating this allowes the restorer to identify what does or dose not need attension

I have heard of this process being done quite a bit in America with good reports. When the aforementioned "Rustang" was resurrected, there was a degree of discussion about it, but if I remember correctly there was an issue finding someone reasonably local that did it and I also think the jury was out on the process for similar reasons to what I mentioned about soda blasting - liquid leaching out of seams at later, inopportune times.
That may well be an unfounded fear and I have no first hand experience with the chemical dipping. The body shell of the "Rustang" was sad, very sad. That said, I think that sending the complete shell out for sandblasting was the right choice for that particular car, which is now a RHD road registered race car. The cost of blasting was easily offset by the massive time savings and I can honestly say that no damage was done by the blaster who was a true master of his art.
I would never contemplate blasting a car at home using handyman gear, although I would definitely spot blast difficult areas.
I have had some really good results using a cement mixer and a couple of shovels of blue metal chips to strip suspension components and other things that can handle a bit of rough and tumble - de slags oxy or plasma cut components like a charm too. Chuck it in the bowl, turn the mixer on and come back half to one hour later and voila.

The question of but joints or lap joints will be determined by how it was done on the original, if you are
doing a restoration it needs to be identical, if you are only doing a recondition/repair then that is a different matter

That is a very fair point.
When judging concourse restorations, the judge will examine such things even down to the style of screw heads used.
I should imagine that any judge would have a hard time picking Mig, Gas or Tig welds once ground and painted, but they certainly could pick a seam weld versus a spot weld or lap construction versus a butt weld.

[Marc]

As far as rust removal from car body parts, no one seems to mention neither molasse bath nor wet blasting with a decent size pressure cleaner and a sand nozzle. Is it not done in Australia?

[Karl Robbers]

As far as rust removal from car body parts, no one seems to mention neither molasse bath nor wet blasting with a decent size pressure cleaner and a sand nozzle. Is it not done in Australia?

Can't comment on the molasses bath, but wet blasting is used in certain applications where dust control is a major requirement. The main place I see it used is our local shipyard and boy can it remove thick coatings like Luke Skywalker's light saber. I believe that recovery and recycling of blasting media is much harder with wet blasting than air based processes and thus the cost is higher. I wonder how desirable it would be to use high pressure water on a car body with exposed seams? I've seen some smaller units for sale and when I researched them, the general consensus was that the feeding of the grit and mess were their biggest weaknesses.
I think that whatever type of blasting used for a full on car restoration, the best approach will always be to take it to an experienced contractor and have them do it. A quality blasting set up is expensive and requires plenty of air or a big pressure washer. If only spot blasting is required, then an inexpensive handyman unit will suffice.
With the right solution, electrolytic rust and coating removal could be a winner for removable components such as doors, bonnets and similar components.

[WelderMick]

Straying further off topic... but here's a DIY wet sandbaster setup.

http://www.youtube.com/watch?v=7ZnUi...07077&index=29

[soundman]

Mstly the only reason wet blastingis used is because sand blasting can not be contained and there is a dust problem.

Most boat yards and slips, do not have the ability to bring the whole boat into a bast chamber, so the either pressure clean or wet blast on an open hard stand.

recovery of the bast media is virtulaly impossible.

Remember boats all get wet and are constructed in a manner to suit this.

Car floor pans have all sorts of laps, cracks, groves and other enclosed places.

Introducing water or any other liquid into the situstion is just going to promote corrosion.

cheers