Cast manifold welding in Edinburgh?

[Nial]

We've got a P reg civic that's still going fairly well but at 11 years old isn't worth a lot.

It's just passed the MOT except the exhaust manifold's got a 5cm crack which is a fail.

Unfortunately the catalytic convertor's integrated with the manifold and the only source
of a new one seems to be Honda, at £530 odd. This is probably about what the car's
worth.

If I could find someone who could run a 5cm cast weld down the crack it would keep the
car on the road for another year. It doesn't need to be a brilliant weld, as long as it
holds together for the MOT re-test it'll do. It's been cracked for the last year or so and
hasn't affected the performance.

Ideally I'd like ot find someone who can do this in situ, the manifold's a bugger to get off.

Thanks, in advance for any pointers to someone who can do this,

Nial

 

[malcolm]

You were talking about picking up an arc welder - if you just want it to get through the MOT it might be an option to pick up the welder, some nickel rods and give it a shot yourself. Failing that use the MIG with stainless wire. Could do either in situ with the earth clamp on the manifold.

Can imagine a lot of places not wanting to do it - lots of mechanical and thermal stress in the manifold which presumably caused it to crack in the first place - wouldn't expect a repair to last.

 

[runnach]

Probably require bridging beads both ends of crack to stop prorogation, cant see it being a winner insitu or bench weld job, but if it last as long to get MOT cert, then your quids in......good luck with repair!

Ps, sorry I don't do cars

PPs, cold welding maybe?

 

[piman]

Hello Nial,

also to stop propagation of the crack, drill a small hole at the very ends of the crack.
A couple of options:-, braze the crack or is it possible to get a clamp around the cracked area in which case I think that a patch and exhaust cement would satisfy the MOT man?

Alec

 

[Nial]

Car

> You were talking about picking up an arc welder - if you just want it to get through the MOT
> it might be an option to pick up the welder, some nickel rods and give it a shot yourself.
> Failing that use the MIG with stainless wire. Could do either in situ with the earth clamp on
> the manifold.

I never got round to picking up an arc machine and don't really have time to practice before
trying this. I don't have any stainless wire either so the MIG's probably out.


> PPs, cold welding maybe?

How do you mean? I've seen empoxy like cold weld stuff but nothing that would take the
heat of the exhaust manifold.

> A couple of options:-, braze the crack

I'm not sure I could get enough heat into it, although I suppose it'd be pretty hot just after
the engine's been on.

And I don't have any oxy-aceltylene gear to get it hot enough.

> or is it possible to get a clamp around the cracked area in which case I think that a patch
> and exhaust cement would satisfy the MOT man?

Unfortunatley it's just near the join of two header pipes so a clamp and paste is probably
out too.


Thanks for the suggestions guys, any more appreciated.


Nial.

 

[Wozzaaah]

If you can get some paste into the crack to stop it from blowing it would be good enough to pass an mot. A tester won't/can't fail it if it's not blowing or unsafe.

 

[piman]

Hello Woz,

"If you can get some paste into the crack to stop it from blowing "

it will never stay there without some sort of mechanical restraint.

My only other non welding solution is to make a steel patch to cover the cracked area, using paste to seal, and drill and tap the manifold to secure it. As I imagine the manifold will be relatively thin the screws will need to be small diameter and quite a few of them.

Alec

 

[Nial]

> it will never stay there without some sort of mechanical restraint.

I've had another look at it and think I _might_ be able to get a jubilee clip round it,
perhaps with one at 90 degrees round the down pipe to hold it in place.

If I can get this on then I'll pack the crack with gun gum, paste it on top then cover
with a mild steel 'bandage' and try to hold this all in place with the jubilee clips.

It'll hopefully be enough for the MOT!


Nial.

 

[peterd51]

Hi,

I ran some mig weld along a small crack in a manifold using MS wire and it held for a least a year afterwards.

I warmed the manifold up first with a butane gas torch, did the weld and let it cool slowly.

Maybe I was just lucky?

Regards
Peter

 

[Nial]

> I ran some mig weld along a small crack in a manifold using MS wire and it held for a least a
> year afterwards.
> I warmed the manifold up first with a butane gas torch, did the weld and let it cool slowly.


Hmm, this might be worth trying underneath the gun-gum 'patch'.

If I run the engine for a while at reasonable throttle first it might heat things
up sufficiently! Only problem is getting the earth wire off the ECU and starting
the weld before it all cools down.

I'm looking at this tonight, I'll report back.

Nial.

 

[malcolm]

Stainless wire is £10 for 0.7kg at Halfords. Don't go attempting cast with mild steel wire. It'll crack. Stainless is softer and will crack less.

 

[Nial]

Stainless wire is £10 for 0.7kg at Halfords. Don't go attempting cast with mild steel wire. It'll crack. Stainless is softer and will crack less.

Bugger, I was in Hellfrauds to get some Gun-gum and jubilee clips just in case. I didn't
read this until late last night and had gone ahead with mild steel wire. This just has to last long
enough to get through the MOT. If it cracks badly again I'll spend a day and get the manifold
off for welding.

I tidied the crack up with an angle grinder/files to try to get a shiny surface along the
crack. I then got the MIG set up for putting a fairly beefy weld down and took the car
for a lengthy run to get the manifold heated.

Before starting I removed the battery earth strap and the fuse to the ECU.

The first short test run of weld turned out really well, but the second run was very porous.

Then I remembered I'd turned the gas off before taking the car for a run. The MIG then
started playing up and was getting wire feed problems which I've never seen before. The
wire seemed to be sticking down the liner and the with the feed rollers creating a tightly
bunched mess just before the liner input at the start of the hose. This happened three
times before I cleaned the rollers with alcohol and things started working a lot better.

This had taken ~20 mins to sort out so everthing had cooled down. I got a fair deposit
on what I thought was the extent of the crack although it was one of the roughest
looking welds I've done, especially down the back of the pipe where I couldn't really
get the torch in to it properly.

I started the car to test for blowout and realised the crack extended further than I
thought round the back. I borrowed one of my wife's compact mirrors and saw where it
was and that I'd wouldn't get the mig to it without taking the manifold off. This was just a
fine crack so I covered it with gun gum and put a patch over it held on with two jubilee
clips.

It looks bloody awful but I'm pretty sure it's not leaking any gas so if that's all that's
required it should pass the MOT OK.

Lessons learned...

The weld seemed to take to the cast metal OK, I'd say this was better at the start when the
manifold was still quite hot. As Malcolm says stainless would probably have been a better
bet.

If you're having strange wire feed problems clean your feed rollers. The two rollers in
my MIG don't seem to be 100% parallel, they were quite greasy and the wire seemed to
be slipping out of the groove in the drive roller somehow. When these were cleaned the
machine seemed to be working a lot better than it has for a long time.

Thanks for the pointers guys,


Nial.

 

[Nial]

Result!

Car passed the MOT OK, the guy said that he didn't look at it very hard but it wasn't
blowing which is all that's required for the MOT.

£230 odd (front tyres, brake pipe, service & MOT) to keep the car on the road for
another year can't be too bad.


Nial.

 

[Wozzaaah]

Sorted!

 

[Puddles]

If anyone is interested this is how I’ve repaired cast iron for about 30-years! You boys in the UK may have to convert a few things!



First off there are six different types of cast iron so you need to know the type of cast iron you are dealing with. Manifolds and cylinder heads are Gray cast iron. If preheating can be used, the preheat temperature for shielded arc welding (stick) should be held between 500° and 1200°. When oxyacetylene welding you should preheat between 900° and 1200°. You should never let the object being repaired get over 1450°. Maybe think about making a jig. I suggest you take a piece of flat bar and match drill the holes of the manifold, then bolt the manifold to the flat bar, prep the crack for welding. Take a weed burner and preheat the manifold uniformly as possible. Make your repairs, then place the manifold in your kitchen oven at 500° for 24-hours. I would purchase the proper temp sticks from your local welding supply.

Nickel 99 can be cut, drilled, milled, and ground. Ni-55 can be ground. The low nickel rod can't be even ground.

 

[ngt]

Grey iron looks like this. It has long strains of graphite and the grey areas are perlite. There are lots of electrodes for cast iron.
Found four of them in a local shop here in Greece
1) 70% Ni and 30% Copper
2) 98% NI
3) 53% Ni and 43%Fe 2% Cu (Has Higher Strength)
4) 50%Ni 46%Fe plus many other ingredients (says for dirty cast iron)
Which one is Better ?? And how do i calculate the size of my electrode (i would be tempted to try a large electrode with 110+ amperes...)?