Advice required on welding holes in my Manta floor panel

[MSG]

In this picture below you can see some water in the rubber bung when I uncovered the bitumen layer!!

[blueosis1]

can you not buy something else cheap to leave on the road.
then you can move this somewere else to work on it properly.
shame to let a coupe go to rust or at worst get crushed.

mark

[MSG]

You are rest assured it won't go to crushers yet, doing everything possible to restore it. for me it brings back over 20 years of owning it!!

[MSG]

Out with a grinder, I have cut out all the rusty rotten steel, grinded off the stubborn rust that the wire brush wouldn't touch, looking forward to do my first ever mig weld tomorrow, when the thing comes over, going to go out no0w to get some steel plates 1.5mm galvanised and some 2 mm for repairing the jacking point and chassis runners. Probably end up making it even stronger than original strength. Won't be making any short cuts now, my nose filter got blocked with so much rusty dust, should have worn face mask.

[Dav1d]

MSG, I had an orion with holes like that.
At the time, Partco autoparts sold floorpan sections which I welded in over the holes (rust cut out first) which greatly cut down on the amount of shaping that needed doing.
And, as I welded all the way around, it greatly stiffened the car up too, which was great around bends and corners.

[mantasport]

Don't use Galvanised steel for repair panels as the fumes it gives off when welded are toxic.
Just mild steel sheet is fine (available from most Motor-factors like Partco etc)

[MSG]

Ok thanks for that advice on galvanised sheets to avoid, Can I use zintec or is it the same effect as galvanised sheets since galvanised is a dipping process and zintec is a electroplating coating of zinc only a micron thick.

If I can get just rolled mild steel then that will be it.


Just raised the car with the jack the car came with, just to see where the stress points are weather it will crumble, so now is the time to think if it needs to have a new jacking plate welded in, and yes a slight buckling at the jacking point means it needs to be strengthend with a thicker material. I will probably do that than to cut out the entire jacking point as this will significantly weaken the structure, reinforcing the original would be a better option.

[jayporn]

I've got the exact same thing with the jacking points on my corsa with a hole above it, my plan was to replace it with one chopped out another car, Had an idea i could use some square tube as i've some offcuts lying. Might work for you

If you use galv you might need to clean up the edges before welding it or it'll spatter. I've never tried zintec though.

A vice will be handy, for hammering/shaping patches. The cantilever tin snips are excellent for cutting chassis plate.
If you going to plate over the jacking cover then drilling holes and plug welding might be an idea to fix it at the bottom.

I always weld a small metal strip close to the job to attach the welders earth to.

Good luck on the welding

[MSG]

Oh well, never thought I would ever get an oppertunity to weld a car, and I am going to definitely try and make a good job of it for sure, jacking point one should be able to use a galvanised steel pipe used for water or gas, I have access to various size pipes so that should not be a problem, I will need to get 2.5mm steel pieces from a metal fabricator i know, to be used around the jacking point and the main runner, he would even cut them to sizes i need, so i will be making cardboard template for all the pieces I need, and ask him to guilotine and where necessary bend the angles i need.


Aparently, the garage who conducted the MOT also failed one of their own repairs they carried out a while back, they used a thin sheet metal probably 1mm and it has rusted away badly, that is because they never treated or removed the old rusty posrtion and whacked this plate over it, this is why i never wanted them to do a quick bodged job to get through the MOT as I am sure doing so would be extremely risky, I doubt they would have bothered removing seats and carpets, and the guy who does the welding told me how he hates welding, hence that was also the main reason why I didn't want to leave the car at the garage for them to do the patching.

[jayporn]

You'll be fine with it hardest thing is getting the welder set up nicely, welding upside down is a pain though. I find trying to hold the torch horizontal when working against gravity helps + a touch more amps. Maybe keep a slightly longer wire than normal as it'll want to burn back and ruin your contact tip (if you melt the wire on to it a quick buzz of the grinder can fix it) , And try and get the metal cleaned up good.

I painted the back of my sheet with red oxide before i cut it into patches, probably burnt it off when welding but suppose every little helps lmao

[MSG]

Thanks jayporn, some good advice there, yes i am going to do everything whilst the oppertunity is there like squirt as much waxoil into the runners to prevent any future rust taking place, waxoil is a best thing you can squirt down the runners with a small spray head attached to a flexible pipe and sent down the runners whilst you have access to it now, I know welding may burn some off, same applies to all the sheets I will try to prime the underside even though some will burn off.

Today i concentrated on the passenger side, cleaned all loose rust off, cut down to good metal, grinded the edges, most of my welding will be done from the top, and some tacks will be carried out from the bottom, after the MOT everything will be sealed properly and lowest point on runners will be drilled to drain any water that may get in.

Although i have nevr done welding, but i know what is good weld and what is a bad weld, and nothing less than a perfect will do here. no hole will be left unturned.

Oh, may be I will use a range of neodium magnets I have to overcome the gravity!! No way the blobs are going to run away from the intended target area!.ready to take this chellenge on. If that doesn't work i might tip the car on its side!! (lol) put an old matterss down first!!

[garymanc]

whilst your at it ... extend the sunroof drain tubes as the water drains into the sills like so

and drill a hole so the water goes on the road,also under the battery is a drain hole block that off as that goes into chassis legs.
also water gets inside car from a poor seal on bonnet pull rubber gromit you will also notice this on the battery tray.
and i reckon you noticed the rubber sponge stuff under the carpet acts like a sponge and stores all the water bin it!
as for your roof thats caused because there is foam around the sunroof again this draws in the damp... best off luck

[garymanc]

have a read through off this thread to give you ideas on repairs
Manta B Project Underway! - Opel Manta Owners Club

[MSG]

Thanks garaymanc, that thread realy amazing how bad that white manta was especially around the swan neck chassis runners, compared to that i am very lucky, mine were bad once and the MOt garage patched it up, but it won't be too long before they flare up again, cause they don't bother killing rust and prevent it occuring again.

that roof swop seems to be a very complex operation, and needless to say i won't be able to do that on open public roads, you need a garage, i will just have to cut away some of the rotten steel and either weld small pieces or if only very tiny perforations, rust treat and then it will be I am afaraid a filler job.

My sun roof is jammed stiff, i am not even sure how it once opened, so I have no idea now where to force it; in order to force open it, perhaphs you might be able to confirm that for me, I think it slid rearward, if i can remember it did not pop up and then go backwards like it does on a cally.

[mantasport]

Don't spray waxoyl inside anything until after all the welding is done!
Its highly flammable for the first few weeks while it sets off, if you set that on fire inside the chassis rail you won't know about it until its spread too far for you to put it out at the road side.

If you goto your local car parts place i'm sure they will have some weld-thru etch primer (either zinc or copper)
spray that inside anything you're about to cover up with new metal, and on the back of the new patches aswell.
Then once all the welding is finished go around everywhere you can get to with Waxoyl

By the way waxoyl isn't the best cavity wax/ rust prevention product out there but its the most common and easily available.
Personnaly i always use Bilt Hamber products as they are far better.

[MSG]

Thanks Mantasports, I am going to order some today then before the patches goes in, will be phoning them in billericay/essex in a min, lines engaged at the moment.


That swan neck chassi is now scaring me a bit, the MOT garage who placed a patch over the corroeded rupturing section couldn't have taken away the rotten stuff out before placing the new patch, orthey should have done that along with cleaning any rust and treating it, so I may well have to gring those patches off and expose the swan neck area one by one and treat each section with the stuff (Bilt Hamber) and redo the patches. But this I will have to do later on as the first thing i need to do is fix the ones that the car failed on, and get the MOT to renew the road tax before the end of the month.

[MSG]

Bilt Hamber do a lot of products for metal preservation, and I am not so sure what is the best one I need, I spoke to a very helpful chap there and he expalined thoroughly what each product is intended for, he suggested using the gel (Deox -jell) which comes in a bottle and leaving a thick layer over the rusty surfaces, for up to 48hrs,and said that in some cases 24hrs would be enough for it to remove the rust,

after which I can use Etch weld, which resists welding heat, and will hopefully protect inner inaccessable areas of the chassis runner.

externally there is no problem as you can always get to it afterwards, and there are many other producs on the marke for that.

For other cavity protection he suggested using Dynax - S50 which comes in a spray can and a long tube that you insert in cavities and it will spray the inner cavities like the waxyol does.

So i will probably go for these today and order the Jell, and the etch weld,

another product called Rust converter...this won't be so good cause it converts rust into some harmless substance and leaves this protective coating but easily burns with welding heat.

[MSG]

I have ordered the 3 items, for in under 50 quid, including around a fiver for the delivery charge, sadly the stuff cannot be deliverd the next day! lazy sods!!

I asked for a special next day delivery but no can do!! bad for their business.



Also suddenly found my Micra had run out of MOT on the 26th June!! and its resident's parking permit ran out on 30th June, but i had renewed it 20 days before and forgot to place it on the screen and got myself a ****in £30 ticket to pay!! bastards takeing a piss out of my poor memory!

Whilst driving the Micra to the MOT garage, a police astra just turned from a side street and started to follow me, and i thought any minute their ANPR is going to tell them to stop me for No MOT!! but guess what, it didn't, they did not even look at me!! luckily I had phoned the garage to cover me (prearranged)
Happily the Micra passed Ok but just on the CO emissions right on the border line, Max allowed is 0.20% and mine were 0.20% thats was close shave!!


On the way back, passing a hand car wash yard, popped in and had a chat with the owner who is happy to let me store and work on my Manta and use his electricity for around 50 quid a week, obviously in the open yard but all metal fenced up, so if my repairs aren't finished by 31st July outside my house, I now have some choice to take it on his yard and finish it off there and keep my car of the road, and SORN it. So hopefully this guy won't change his mind and I will probably take my Calibra for his to hand wash and promise him lot of work his way, you need to make good friends with people like that!

[garymanc]

the sunroof should just slide back when you pull the little lever down,i allways put some clear grease around the seal to help keep it watertight.

[MSG]

Managed to undo it, just rememebred how it once worked, yes you slide it back and it was stiff, I have now washed all the dirt and debri all around it, and yes unbelivable how the drain tubes feed into the sill area, no wonder it probably rote due to that, could have extended the tubes and drained through a hole in the sill directly onto the road surface.

[MSG]

My Mig beast has arrived, its heavy as a feck! 25kg, spent the last couple of hours reading instructions and warning notes, will need lots of practice before i start using it on the car, got some old metal bits including some steel sheets that I can practice on, fix my metal BBQ to see if I am any good, otherwise it is a complete waste of time and money. No one can ever be a good weleder straight off a book, will need lots of practice.


aparently i can only use max 60 amps welding current as that is the limit for domestic mains 3 pin plug supply and any higher will blow the 13amp fuse, so may be I need to use a cooker circuit fused at 30 amps if ever I need more than 60amps to weld.

[blueosis1]

chassis legs are a pain to repair and need to be done right.thought i only had a small scab to repair but got a bit worse


mark

[MSG]

That is how it seems to be, like what you see is a tip of the iceberg, and it is not until you start hammering the adjoing areas that you realise the true extent of the damage.

Any way took my Mig into the back garden to assemble and load the flux wire etc, reading instructions etc, part assembling the unit, then had a quick go at trying to weld two small pieces and did not sucseed in doing so, even at lowest wire feed, the wire seems to be feeding out far too much than I am abale to run the nozzle along, so it will take me hell of a lot of practice to get any where, looks like I will end up getting someone else to do the job for me in the end, what a bugger!

[8valve-craig]

Keep practicing, and dont try welding with the wire speed turned all the way down! put it at about 1/3rd way up. Cut your wire to prodrude out of the tip approx 3mm, Make sure your earth is attatched to clean steel as close to the weld as possible. And be sure when trying to weld two pieces of steel together to make sure the arc contacts both pieces of materiel in a sort of zigzag motion. Dont try welding in a line as this will not heat both pieces of metal therefor not joining them. Seriously keep at it and you will soon learn from your mistakes.

[blueosis1]

find some scrap metal and keep practicing.must admit my first attemps were to blow holes in it.a lot of mine were done by a mate,i had to prepare everything and cut the plates to fit.used to nick the cereal boxes to make patterns with.
stick with it ,to good a car to let the tin worm eat.

mark