View Full Version : Evaporator pitting.

25-10-2005, 01:28 PM
Hello all.

Just been looking at a Luve Contardo evaporator that we installed into a walk in cool room about 14 months ago in a chinese resteraunt.

Bloody thing is now like a pin cushion full of tiny leaks everywhere.

Obviously something being stored in the room is causing the problem.

Strange though only seem to have this problem in this particular resteraunt.

Blower is going to be changed but I have now educated the owner on covering up any food that may cause problems. When I install the new evaporator I am going to spray the coil with protective coil coating which comes in a can and goes under the name "Kirby Cote" here in Australia.

Have any members had experience with this stuff or anything similar. If so is it beneficial or an utter waste of time?

Thanks in advance:)

US Iceman
25-10-2005, 02:08 PM
Hi Temprite,

I have used something similar for the same reason. I tried a spray on coating once, but do not have long term experience with it. The shop closed shortly after the coil was installed.

If I remember correctly the coating was similar to a plastic film that hardened. Some other US manufacturers have a similar process I believe.

I have seen several coils like this. I think it is caused by the food or ingredients.

Is the coil made of aluminum? It may be the grade of aluminum used also.

Johnny Rod
25-10-2005, 03:46 PM
I read an article a while ago about aluminium being pitted by small amounts of formic acid on heat exchagers where they had aluminium fins. Notice anything smelly in the room? Acetic acid smells like vinegar, formic is similar. Have they been cleaning the evap with anything?

25-10-2005, 08:36 PM
Hi Temrite.
Had the same problem in a Cheese Maturing cold storage.

Before installing the new coil, I had it sprayed with epoxy paint, 6 coats, its working fine now for a few years.


chillin out
25-10-2005, 09:34 PM
Have they been cleaning the evap with anything?
He is talking about i chinese restaurant.....

In my experience they dont clean anything.

(No offence Ic shi, but the restauranteurs over here could do with going on a food hygiene course...not all , just most)

Chillin:) :)

26-10-2005, 10:50 AM
I came across the problem a few years ago and could not find the source of the chemical so i ended up replacing the coil with a stainless steel one, never looked back,


26-10-2005, 04:31 PM
Good choice, but at what price?
Not all customers will pay it.


Andy W
26-10-2005, 05:20 PM
The quality of some of the copper used to make coils varies, look at Foster for example they are the kings of poor quality evaporators and vapourizers that just rot away, last week I scrapped a 4 year old Foster freezer with a rotten vaporizer which totally filled the system with water. From experience cooked meat coldrooms show the biggest obvious change in appearence of the copper, I put a coldroom in for a butcher 18 month ago, the copper has totally changed colour to a more purple colour including the drain pipe, the same thing happens in Foster cabinets as installed in most Chinese take aways etc obviously some kind of reaction to what I dont know. Williams started to plastic coat all there evaps for cabinets, I have changed dozens of the old evaps and replaced them with the new coated evaps.

26-10-2005, 08:12 PM
Obviously something being stored in the room is causing the problem.

Strange though only seem to have this problem in this particular resteraunt.

Have you considered taking a swab from the coils and getting it analised?

Offer the owner the option of paying for it or buying a new fridge.

home made vaporizer (http://homemadevaporizers.info/)

27-10-2005, 12:24 PM
Thanks for the replies all.

Thats what I like about this forum.It gives you a varying range of opinions other than your own.

I would love to put a stainless evap in their but customer will not pay for it.

Who sprayed the evap with epoxy coating was it some one who specialised in treating evaps?

The only smell I am aware of is that smell you get on your hands that takes days to dissapear (copper oxide?)

I think I will give the "Kirby cote" a go. Its got to be better than doing nothing. I read the cans today and it apparantly stops corrosion due to salt air, which could be good for condensers in our neck of the woods, and it doesn't affect heat transfer of the coil. Besides if I dont use it the cans will sit on the shelf for another three years:)

27-10-2005, 01:31 PM
U Searle End Of Ur Problem

15-11-2005, 07:19 AM
I am in the commercial manufacturing of display cases and

we will void a warranty claim if the customer has kept

Vinagerettes in the case

An old tail is vinegar products are good for cleaning
a case

but it is highly corrosive at the same time

Imagine this vinegar being circulated through a system day in day out

not much left of your copper once it has started at the evap expelled heat at the condenser .

How much copper is there in a system ?

It is eaiser to replace the whole system then to replace
the components that are showing the signs.

15-11-2005, 12:28 PM
Thanks fridg

Have taken it on board:)

15-11-2005, 01:37 PM
temprite in my experience have always had the drama where the u bends on the coils leak, as in the kirby evaporators as they are quite thin in the copper there.... Installed a new evaporator in a particular coolroom that had previously leaked on the u bends, and sprayed kirby cote just over the u bends to protect them, seems like a good product, but have not had long term experience with it...... I wonder how much if any if it affects the heat transfer of the evaporator????

16-11-2005, 02:41 AM
Who manufactures stainless steel evaporator coils?

17-11-2005, 11:45 AM
are you going to use the kirby coat on the pipe work as well? we look after a place that has corrosion resistant coils.the coils are fine but the liquid line is pitted to buggery

24-11-2005, 11:14 AM
I'm dubious of the value of Kirby kote. It comes on some of their smaller coils and I've seen them eat out damn quickly if used in a deli cabinet where high acidity can get to them. To me it's a cheap alternative to using the correct wall thickness in the coils in the first place.

I know you can get thicker wall coils but can't think who supplies them. If I find out I'll post it.

30-11-2005, 11:55 PM
Hi Mate. Kirby Dip some of their smaller coils in the stuff. We use to use it after braizing the evap. Make sure you use a mask in confined spaces if welding after you put it on. It stinks like ****. Gives you a nice headach when it burns.

Good luck.

01-12-2005, 06:22 PM

Check these web sites.




01-12-2005, 10:01 PM
Who manufactures stainless steel evaporator coils?
Goedhart of The Netherlands