When It Says Cut Out the Rust ...

[cobolman]

I'm new to welding and trying to learn on car bodywork. You don't need me to tell you that it's not easy

A common piece of advice that I read is to "cut out all of the rust"

My question is: What do you consider as rust?

I've attached a pic from a Mini inner wing. How much of this, would you say, needs to be cut out?

Thanks

ps: In case it's pertinent: This car was sand blasted and then painted in primer. I took of the layer of primer to show what I'm dealing with

 

[brightspark]

cut out all the well pitted pieces . any surface rust would disappear if its been blasted

 

[Tupers]

You really need to go back to shinny smooth steel for best results.

If it was in my workshop and I was trying to preserve the inner wings I would be cutting back to the red line.

 

[bert]

I'd be replacing the whole inner wing, if it's that bad there it will be worse on other places you have not yet got to. I've done maybe 15 classic Minis and most got complete new front ends

 

[Blobber]

If you go down a bit further it looks like rust is hiding all along the tops of the louvres/swaged holes?
Really doesn't look like it was blasted

 

[Erie Fred]

When blasting, it always goes further than the customer thinks it should...."But I said to blast it lightly".
Just a few rust specks, and it ends up looking like a speckled trout when done.

If the "metal" can't take sandblasting enough to remove paint, it's not structural anymore.

 

[brightspark]

When blasting, it always goes further than the customer thinks it should...."But I said to blast it lightly".
Just a few rust specks, and it ends up looking like a speckled trout when done.

If the "metal" can't take sandblasting enough to remove paint, it's not structural anymore.

if the metal pinholes its well knacked and and thin. you can blast a thin 1 gallon oil can 2 or 3 times and it still wont go through it

 

[brightspark]

i used to do a lot of blasting for folk, car wheels alloys and steel motorcycle frames tanks and parts using supafine grit .got the odd fools saying you have ruined my parts as they now have pinholes in the metal i just said they were well knacked and rusted before i started so wot do you expect

 

[sasquar]

You really need to go back to shinny smooth steel for best results.

If it was in my workshop and I was trying to preserve the inner wings I would be cutting back to the red line.
View attachment 470137

oh, thats an early one as well by the looks of things.....

yep, i mean id cut it in a straight line, (i shouldnt joke, i have no idea how to even draw on a picture tbh) but thats where i would be cutting. Worth checking out where the front panel joins onto the inner wing as well, plus the top corners around the interior vents, as it may well be more effecient to replace the whole panel if its also shot in those areas (this doesnt necessarily mean you should though, sometimes its nice to retain original metal).
Well worth checking out Paul Wiggintons videos on YT, hes a master at restoring the early cars (been doing it years and years) and his son (im assuming) seems damn good at making videos. I was expecting them to be a bit of a tough watch (not doubting his metal working tallent, but ive seen quite a few people dabble at YT and not be especially watchable, but he seems to be the exception. If you have a scroll through some of his videos, hes done a couple that are more 'preservation than restoration' which is to say that theyve saved as much orginial metal as poss, which are well worth a watch......

 

[Agroshield]

yep, I mean I'd cut it in a straight line...

Should we say that it is probably unwise to remove the entire red-lined section in one go? If you do so, you lose all reference points. Maybe cut out a bit at the front, insert, line level and tack patch and then move along to the next section. It all ends up as new metal but not as one huge piece.

 

[Shedendman]

As mentioned,replace,if thats if you can afford it(around £250+/- for that part),if you cant then its a repair,good luck with that,just take your time over it,cut a template,mark and measure a 1000 times,you should be fine
Good to see you've got it braced though

 

[Morris]

If that's what is under the primer I would be concerned about the quality of the blasting done. I would expect to see clean pitting, not rust filled divots.
Also what primer was used?

 

[dave h 2]

Appalling blasting, did they say what grade they would blast it to? That panel is eaten at least halfway through and if done properly would have a fair number of holes.
Cut to the red line except where the spot welds are on the far right.
At least you have started right way by blasting, had it been done properly any welding would have been easier. Suggest you sand off any other rough areas, they may have covered up other issues with primer.

 

[Nomad]

Before doing anything go around the rest of the shell and make sure you identify all the areas that need attention - most of my new projects come with a few sections that need welding...
I have fitted new panels but prefer to patch repair, personal choice but often because I'm working on cars where panels aren't available, I recently fitted new pattern floors in a project and "fettling" took a lot longer than I was expecting.

Depending how confident you feel :
Change the right hand end of the red line above so it follows the row of spot welds but stops a couple of inches before the bulkhead (easier to tidy the weld from both sides)
Mark out the red line using a straight edge before cutting (much easier to fit the new piece)

Before you remove the rusted original section :
measure key dimensions (from the top of each inner wing vent to the top lip) so the new panel goes back in the same place
make up as much of the replacement piece as possible (leave a decent overlap to trim later).
My latest tool is a die grinder, great for tidying welds where an angle grinder won't reach - ie your the under bonnet weld near your bulkhead.

 

[cobolman]

You really need to go back to shinny smooth steel for best results.

If it was in my workshop and I was trying to preserve the inner wings I would be cutting back to the red line.

Thank you. The clarity here is very helpful.

 

[cobolman]

I'd be replacing the whole inner wing, if it's that bad there it will be worse on other places you have not yet got to. I've done maybe 15 classic Minis and most got complete new front ends

I've ordered front repair sections from M-Machine. I was loath to do this as it's a 1960 Mk 1 Mini and I wanted to keep it as original as possible. But as the many responses on here indicate, sometimes the steel is just too far gone.

ps: I've also ordered new front wings and front panel because, as you point out, a complete front end is almost always needed.

 

[cobolman]

If you go down a bit further it looks like rust is hiding all along the tops of the louvres/swaged holes?
Really doesn't look like it was blasted

There is indeed a bit of rust hiding there. Your view on the blasting seems to be well taken up by other commenters too and so I've been revewing what happened. They guy I had do it was highly recommended by a local specialist. He was specific that he uses a very gentle approach to blasting so as not to destroy old steel. Maybe too light a touch?

 

[cobolman]

oh, thats an early one as well by the looks of things.....

yep, i mean id cut it in a straight line, (i shouldnt joke, i have no idea how to even draw on a picture tbh) but thats where i would be cutting. Worth checking out where the front panel joins onto the inner wing as well, plus the top corners around the interior vents, as it may well be more effecient to replace the whole panel if its also shot in those areas (this doesnt necessarily mean you should though, sometimes its nice to retain original metal).
Well worth checking out Paul Wiggintons videos on YT, hes a master at restoring the early cars (been doing it years and years) and his son (im assuming) seems damn good at making videos. I was expecting them to be a bit of a tough watch (not doubting his metal working tallent, but ive seen quite a few people dabble at YT and not be especially watchable, but he seems to be the exception. If you have a scroll through some of his videos, hes done a couple that are more 'preservation than restoration' which is to say that theyve saved as much orginial metal as poss, which are well worth a watch......

Yes, it's a 1960 Mini and there are precious few of them left. That said, if it's to go on for another 65 years, it'll need some help

The upper flanges that the inner wings join to are shot. I've tried delicately applying an angle grinder to get rid of the welds (image below) but it's been a fools errand, I think.

I'm a big fan of Paul Wigintons videos and have learned a great deal from watching them. He has a preservation series underway right now.

 

[cobolman]

Should we say that it is probably unwise to remove the entire red-lined section in one go? If you do so, you lose all reference points. Maybe cut out a bit at the front, insert, line level and tack patch and then move along to the next section. It all ends up as new metal but not as one huge piece.

Losing all reference points is something I'm always worried about. Equally, grinding down welds (without burning through) so it all looks like a continuous stretch of metal, is no easy task either It's a delicate balance, I find.

 

[cobolman]

As mentioned,replace,if thats if you can afford it(around £250+/- for that part),if you cant then its a repair,good luck with that,just take your time over it,cut a template,mark and measure a 1000 times,you should be fine
Good to see you've got it braced though

As you say, the entire inner wing isn't a cheap panel. That said, they're a LOT cheaper than most panels (I'm thinking predominantly of E-Type and Mercedes) I've ordered front repair panels from M-Machine. They're £40 for the RH side and £84 for the LH side. Hopefully, they'll do the job.

The car is currently on a rotisserie (which is what you can see in the pic) But I have also braced the interior as the floor has to come out too! Heart stopping stuff for a first Mini resto when I've no welding experience. I'll certainly learn it here