Heat exchanger repair

[PaulRainbow]

It's plausible what our friend at Volvo said, I just don't buy it. I think it would have eaten that flange in a very different way - the corrosion would not have just focussed where the dissimilar metals meet. Additionally, Parts4Engines gave the specific reason they supply that composite gasket, and to chuck the stainless one supplied away, that they are well aware of the galvanic corrosion issues of this area of these Volvo engines. Added to that, on the other thread related to this issue, a Vetus owner, who had a 30 year old engine, noted Vetus fit as standard a composite gasket and his exchanger flange to the elbow was "as new".

Unfortunately, you'd be better off spending your writing time on the PBO article, that might recover some of your costs, complaining to VP about some corrosion on a decades old engine is like :



It's often hard enough to get them to resolve issues on new engines.

 

[superheat6k]

£400 and the good folks at the Goto Engineering nearly have it all flush and ready to go. Both chambers pressure tested to 15psi fine.

Pressure testing the freshwater chamber:

Pressure testing the raw water chamber:

Original flange pre welding:

Welding process started:

Studs out and ground back:

More building up and final machining and polishing will be done later today, ready for pick up tomorrow!

That is a nice repair, and will likely last a decent amount of time, but not much will stop hot gas impingement.

 

[jwfrary]

Best to avoid high speed round tools on machined surfaces.

bit of scotch brite and a flat bit of wood after the razor blade is my preferred choice.

 

[RichardS]

Best to avoid high speed round tools on machined surfaces.

bit of scotch brite and a flat bit of wood after the razor blade is my preferred choice.

Scotch Brite? Razor blade? On aluminium weld?

Richard

 

[jwfrary]

Scotch Brite? Razor blade? On aluminium weld?

Richard

for the steel exhaust port flange on the head where the old gunky gasket was.

One assumes the repair will be clean and fair from the machine shop

 

[RichardS]

One assumes the repair will be clean and fair from the machine shop

Indeed .... and hence my confusion. The old gasket was actually just a steel plate which was being suggested as a possible source of the corrosion problem. However, for the future replacement composite gasket, then a good clean-up might well be required.

Richard

 

[MagicalArmchair]

Quite so, the welding shop do not have the facilities to mill it flat so they are sending it to another machine shop on the estate to finish making it fully flush, so nope, no more work will be required to it. The Exhaust Elbow is also new, so that is nice and clean.

...hot gas impingement.

Wait... what now?

 

[MagicalArmchair]

They couldn't fit the exchanger on the mill of the other engineering shop. The engineers were not daunted by this and "scraped" it (I was not aware this was a "thing")- the engineer showed me the flange with a gauge and it is super flush and ready to go.

A charming video on what "scraping" is - awesome!

And something more up to date

 

[rogerthebodger]

Ho the joys of filing and scraping a surface flat using surface plate and engineering blue.

 

[Laysula]

Ho the joys of filing and scraping a surface flat using surface plate and engineering blue.

And the joys of finding engineers blue on the inside of the toilet door handle.

 

[Beneteau381]

They couldn't fit the exchanger on the mill of the other engineering shop. The engineers were not daunted by this and "scraped" it (I was not aware this was a "thing")- the engineer showed me the flange with a gauge and it is super flush and ready to go.

A charming video on what "scraping" is - awesome!

And something more up to date

I used to do that on loco wheel brass bearings, had snub nosed chisels to chase grease grooves in them as well. I remember doing a loco axle bearing cheek set with a small hand held grinder, it came out grand!

 

[superheat6k]

And the joys of finding engineers blue on the inside of the toilet door handle.

Engineer's blue does a good job of simulating how a virus spreads.

 

[Rappey]

Terrible stuff when it's in a squirty bottle and the back then bunch of apprentices decide to have a water pistol type fight.
Was a lot of blue faced teens on the bus that night !

 

[Laysula]

Terrible stuff when it's in a squirty bottle and the back then bunch of apprentices decide to have a water pistol type fight.
Was a lot of blue faced teens on the bus that night !

I think that would have been marking blue rather than Prussian blue. But yeh wasn't it fun being an apprentice.

 

[RichardS]

When I have the choice, I always buy Blueprint parts as they sound super-professional.

(and, as it happens, they are a good brand)

Richard

 

[Beneteau381]

I think that would have been marking blue rather than Prussian blue. But yeh wasn't it fun being an apprentice.

Making tea!

 

[rogerthebodger]

Making tea!

Up Norf you don't make tea you Mash tea.

 

[Laysula]

Don't drink Alfs tea.

 

[smithy]

I remember as an apprentice having to do a scraping excersise. I was having a bit of trouble and blamed the surface plate, big mistake! I had to spend the next week scraping that flat. Forty five years ago, never made that mistake again.

 

[rogerthebodger]

I was having a bit of trouble and blamed the surface plate, big mistake!

Goes back to the old saying " A bad workman blames his tools"