1844 replies to this topic

[BusheyTrader]

It's interesting how you're dealing with the rust in the seams.  I asked on the forum and was basically told to cut out metal rather than open them out, chemically remove the rust then fill with zinc.

 

So far I've been drilling out the spot welds to remove perforated panels, cleaning and chemically removing the rust in the open seam then plug welding replacement panels in to place.  I use Bilthamber products to remove the rust and then weld thru pimer.  Their rust remover being water soluble creates a lot of scepticism about them but their products just work.  

 

Adam

[Petrol]

Really going the extra mile with the seams,  but that should pay off with the longevity of the mini.  How are you shot blasting the seams,  have you got a small diy system??

 

Graham

 

Once rust starts it seems to accelerate exponentially. Since there's surface rust inside every seam I have split so far, I'm doing my best to get rid of as much as I can. The cost of a refurbing a shell including a proper paint job / stone chip / underbody shutz / seam sealers / box section wax is significant so I think it's worth putting the extra effort in at this stage. These late model Mini's were not built to last. I guess after about 5 years they started to bubble in the usual areas. I really don't think this has anything to do with the quality of the steel (On a side note, they had huge rust problems with cars built in the early 70's due to poor steel quality but that soon got sorted) On these late model Mini's, it's the lack of protection and poor application of sealants and lack of box section wax. For example the seam sealer has just been brushed on with big voids behind it - not good practice and I have found probably about half a cup full of box section wax on the entire shell! This shell only had a couple of plates on the original sills so it's pretty much unmolested, been interesting to see how it was assembled though and I can understand why they rust in no time at all.

 

I also have a few more plans to stop the rust coming back but need to get it onto a spit. I can't do that yet as the rear wheel arches need to be in place. I'm planning on pouring Electrox for even better coverage, then once the shell has had it's final coat of paint, back on the spit for a real good dose of proper (not waxoyl) box section wax. It will be interesting to see how long it lasts.

 

As far as blasting goes, this is what I use

 

 

Bought the gun on ebay, IRO £20 I think. Blast media is glass and kept in an old dustbin to keep it dry. It just takes me ages to sweep up and hose down after a blasting session. Might be worth a mention that blasting needs a lot of air so a reasonable sized compressor is needed.

 

HTH

Pete

[1984mini25]

 

 I really don't think this has anything to do with the quality of the steel (On a side note, they had huge rust problems with cars built in the early 70's due to poor steel quality but that soon got sorted) On these late model Mini's, it's the lack of protection and poor application of sealants and lack of box section wax.

 

 

The steel form about 88-89 onwards is noticeably thinner than the earlier minis, also the later the mini the less paint coverage. both inside and out it seamed to get.

[Petrol]

It's interesting how you're dealing with the rust in the seams.  I asked on the forum and was basically told to cut out metal rather than open them out, chemically remove the rust then fill with zinc.

 

So far I've been drilling out the spot welds to remove perforated panels, cleaning and chemically removing the rust in the open seam then plug welding replacement panels in to place.  I use Bilthamber products to remove the rust and then weld thru pimer.  Their rust remover being water soluble creates a lot of scepticism about them but their products just work.  

 

Adam

If there is only surface rust, it's better to split and leave the original spot weld intact. Inside of the spot weld won't be rusty. For rust to form you need 2 things, oxygen and moisture, since none of these exist inside a spot weld there will be no rust.

 

Also remember that weld through primer has it's limitations, when you weld the heat burns off the paint leaving no protection at all. That's why I'm forcing zinc in after welding.

 

As far as Bilt Hamber stuff goes, I have had a lot of success with their products and the water soluble concerns are unjustified - I de-greased a crank then washed it in the kitchen sink before rebuilding the engine, this was a complicated engine to rebuild as the crush on the shells was critical - half a thou! I didn't have rust problems though!

 

There are many products out there to help us to keep these Mini's alive but as far as I am concerned there is no "quick fix" It's just a slow painstaking job

 

Pete

[BlackHowl]

I'm exhausted reading this epic thread! Hats off to you Pete. Doing an incredible job. I hope Junior is paying close attention!

 

Seeing the extent of the rust is quite disheartening though given that I'm on the hunt for an MPi at the moment.

[Petrol]

 I hope Junior is paying close attention!

 

 

My daughter has taken quite an interest today. There are some stiffening plates on the boot floor and the original plan was to cut some new steel to weld on the new boot floor.

 

 

On closer inspection these plates are quite thick so I decided to re use them. They are seam and spot welded. I cut through the seams with a 1mm cutting disk and drilled the spot welds out

 

 

 

 

Also finished this seam

 

 

When I first started blasting the shell I swept up the blast media to re use it.

 

 

I ended up with large bits in it which kept blocking the gun. Now I run it through a sieve to get rid of them and it's sorted the problem

 

 

 

Pete

[rally515]

Just a few questions pete: what will you be doing on pitted areas like the rear window seam ? lead load, filler, weld on ?

           Does blasting take a while ?, does it get down to bare metal easy on thick coated areas ?

            When you cut the inner sill out the b-post was hanging freely, would this have buggered with alignment ? or have you measured that too

 

Loving the build so much, helping me in areas now and refernce for future ventures

 

Thanks again pete

 

Cliff

[Petrol]

Hi Cliff,

 

Bloody hell you guy's don't miss a trick

 

As far as the B post goes, it couldn't move forwards or backwards due to the rear wing / door step. Lateral (side to side) positioning was sorted with this small bracket I welded to the floor and companion bin

 

 

Blasting - 

Depends on the gear you have as blasting, as I mentioned earlier consumes vast amounts of air. I wire brush paint and underseal off as it's quicker but blasting doesn't take long once you have all the paint off. Might also be worth a mention that blasting generates heat and can buckle panels if you go at it too mad

 

Pitting / filler

I hate filler, paint always "maps" around it. For example if you fill a dink and spray it, eventually the filler will shrink and leave tell tale signs. I will be filling any imperfections with paint like I did with the door skins. To be honest I will be glad when all the welding / grinding is done on the shell and I can move on to the paint pre prep stage. I will be a little more in my comfort zone then

 

Hope that helps

Pete

 

 

 

[rally515]

Absolutly brill pete, wish id thought of the welding of the bracket   haha, i'l be doing the other sills like that thankyou

 

We have a decent compresdor so i should be ok for air, i was more concerned about coverage of the blast jet and changing nozzles would (i presume) effect the back presdure and therfore not be as good at stripping paint/rust ect... thankyou for that aswell, i'l be buying one of those soon enough now haha

 

Didnt think of those possible issues with filler, i may give pure paint a go, cheers

 

Thanks

 

Cliff

[Petrol]

The blast gun I bought came with some spare nozzles, happen a good job as they don't last long

 

The old

 

 

 

The new

 

 

 

Finished all the seams on the NS bulkhead / floor. This one was a right pita to get to

 

 

 

Couldn't get the hammer in

 

 

So I used a 1/2" drive extension

 

 

Pete

 

 

[Petrol]

The exhaust heat shield sits flush to the floor which is not a very good design, it would be better spaced off to allow an air gap

 

 

 

The studs welded to the floor were too short to space it off, bit rotten and all

 

 

 

Repaired the floor and drilled holes. I will use stainless bolts

 

 

 

The original plan was to wire brush the underseal & Ecoat off the floor. Decided to keep as much of the Ecoat as I could because it's better than primer. I used a heat gun with a plastic scraper to get rid of the bulk of the underseal and cleaned the rest off with thinners

 

 

Shot blasted any rust off

 

 

 

Then primed the bare metal with 2 coats of Electox zinc primer

 

 

 

 

 

 

 

 

 

[Petrol]

Seam sealed

 

 

Also ran a bead over the seam weld

 

 

Zinc primer is a bit soft so I sprayed some colour on to protect it

 

 

Fastened some foam onto the dolly

 

 

 

[nev_payne]

That is one solid floor.

[Petrol]

Thanks nev_payne.

 

The original plan was to get the whole shell in primer but prefer the idea of colour to protect the primer. Prepped half of the front

 

 

Primed

 

 

Painted

 

 

 

This decent run of weather has made things much easier and it's great having plenty of space to work

 

 

Got to do the other side now

 

Pete

Edited by Petrol, 12 June 2013 - 09:39 PM.

[Petrol]

I am trying to plan ahead all the time on this project. The ice will include this

 

 

And these

 

 

The plan is to get all the holes drilled in the shell to fit em.

 

Decided on these for the doors, not keen on the wood stuff and prefer the retro look

 

 

Also decided to fit the original wheels, the centers show signs of fading so bought these

 

 

I'm sure I can sort 4 gooduns out

 

Pete

Edited by Petrol, 13 June 2013 - 08:49 PM.