Renovating A Rusty HPC Kaeser Screw Compressor

[awemawson]

I'm ashamed of my 'Road Compressor' - It's vents on is casing are rusting away to the extent that they are falling apart 

Bought in 2008 in fair but used condition it was intended to run my Hodge Clemco sand blaster to clean up the steel work for the barn that was to become my workshop. It wasn't sparkling then - had obviously been reversed into something stoving in the rear panel but it worked. Apart from changing the oils and filters and giving it a new battery I've done nothing to it. It sits outside in all weathers (hence the deterioration) and gets occasional use. It's been used to inflate the ex Chinese Army field hospital that I used to use as a lambing shed, obviously the sand blaster, and I've plumbed an outside 'claw fitting' input to my workshop air network so it can let me run my cabinet sand blaster continuously.

. . .but it's been neglected. Walking past it today I gave it a slightly more detailed inspection and realised that although the vents on the rear and both sides are badly rusted, they are easily removed, and the rest of the body is in pretty fair condition apart from the stoved in rear panel which can probably be straightened with a large baulk of timber and equally large hammer.

. . . so . . can I remake the louvre vents. Well they are not true louvres, actually being constructed from channel section of about 1.2 mm thicknes and approximately 4 cms wide by 1 cm deep. I have a guillotine, I have a folder but can I fold this section - often channels like this get obstructed by the folding fingers after the first fold.

So EXPERIMENT and find out - so I did and I can - an off cut was roughly cut to size and successfully folded

I've even probably got enough Zintec 1.2 mm steel to do the job if I'm careful.

Now it's the wrong time of year to be doing this job - the season is closing in and once I've made up the new vents I'll want to blast off and re-paint the whole upper works of the cabinet.

However there's nothing to stop me over the coming winter making up the vents ready for the spring - it looks like blasting jobs are queuing up for spring - I've just committed to buying yet another Versatool tooling cabinet that will need 'the treatment'


 

[awemawson]

After a  bit more cogitation I've decided to consider quite a redesign to the louvre vents.

The original horizontal slats are / were the front faces of (presumably) sound deadening foam slabs with the air passing between them. Over the years these slabs have saturated with rain as there's not much to keep them dry. Hence the major rusting.

Most of the slabs have fallen out anyway (well actually fallen IN, into the engine compartment!) so are not contributing to sound deadening, and as I have no neighbours I'm not much concerned with noise. So a much simpler approach would be a plain grill of some sort, or if I can find suitably sized commercial louvre panels make a grill from them. With genuine louvres the slats can slant outwards and fend of the rain unlike the originals that had no tilt.

The equivalent air vents on a 100 KVA Aggreko 3 phase generator that I rebuilt a couple of decades ago comprised perforated slats with mineral wool slabs between, again totally rusted away. With great diligence I did re-create them, but it was a lot of work.

. . . . thoughts ?

[John Rudd]

Great project Andrew,

Re the slats, I’d go with what’s easiest to fab that will keep the rain out….if it means a redesign…

[hermetic]

Looks to me like a test piece for the newly renovated sandblaster! but can you remove the entire cover and do it all at once, and then repair the bits that are too far gone? Always busy Andrew!!

[awemawson]

I'll post some pictures of the inside of those vents when it stops raining - pouring down at the moment.

Yes once I've settled on how to replace the vents the entire upper cover will be lifted off, blasted and re-painted once knocked back into shape. Shouldn't be too bad apart for one small rubber mounted window though which the gauges are visible. Being small it will be a pain to get out and back.

. . . .meanwhile I'm waiting this morning for a Lucas 18ACR alternator to be delivered to sort out the charging on the Ford 4600 hedge flail tractor . . .as you say always busy !

[awemawson]

Still raining but I had to suit up anyway to collect the post so took some pictures.

As you can see the structure of the 'soundboxes' or vents is practically fully disintegrated with rust but the main cover is still very good and solid. Fortunately the vents / boxes just slot into rectangular holes and are screw fixed so can be pulled off without disturbing the rest of the cover.

[djc]

After a  bit more cogitation I've decided to consider quite a redesign to the louvre vents.

Be careful changing the OEM airflow through the machine too drastically. The designers knew what they were doing when they made it that way.

On site, in the summer, our people used to open the lid of the compressor 'to keep it cool'. In this way, they overheated far more quickly and shut down than with the lid closed because the air did not flow as IR intended.

[awemawson]

I take your point but the vents will be in the same place, but without the sound absorbing foam.

If you look at the last three pictures you'll see why they need changing