Dry Ice Blasting
Sand Jet Cleaning
We specialise in using a low pressure sand jetting system that has been used nationwide for various cleaning tasks. The system, in our trained hands, causes minimal damage to an underlying surface and is flexible enough to tackle most property restoration cleaning tasks. The low pressure sand jet can clean surfaces without injecting large quantities of water into the surface, and with minimal surface damage, at the same time, the 'wet' system also captures dirt and abrasive, preventing the health and safety risks associated with dry blasting.
However, there are times when alternative methods are called for, one of which is Dry Ice blasting. Here a surface to be cleaned is blasted with solid CO2 particles, and the surface is cleaned through thermal shock, the massive volume change as dry ice particles turn into gas, and some abrasion of the surface contaminant. A video of the process (cleaning soot from stone) is available here, and a data-sheet of property cleaning with dry ice here. and metal cleaning here
The advantage of this system is that the 'abrasive' evaporates on impact, so the only 'debris' is the material being removed. It is nearly 'dustless' - about as dustless as it is possible to get for an open blast system - however it will still blow cobwebs, birds nests, paint debris etc. fairly liberally!
It should be noted in the picture above that that particular blast nozzle system has a powerful light mounted above the trigger - the bright glow at the 'blast face' is that light reflecting back off the dry ice particules and condensing water vapour in the atmosphere!
Disadvantages are the costs compared to alternative systems, in particular the raw ingredient dry ice evaporates when it is not used, so needs to be used rapidly. On a daily basis, dry ice will cost 50% more than sand jet cleaning, but for the first day of a job, i.e. the mobilisation cost, is about 100% more. The other issue with the evaporation is that we have to gauge how much CO2 we will need the day before the job - and indeed tomorrow's order needs to be placed before 11am today - so if we run out with a job 'nearly complete' at 3pm, it will be the day after next before we can get more dry ice to complete it. , unlike sand blasting where we just take plenty of sand - and if we don't use it, it goes back on the pallet.
It is used widely in the printing industry to clean print rollers, and for mould and weld cleaning.
Machinery Cleaning - Cement
This poor bobcat had been used for a couple of years to unload cement at Hull Docks- and was due to go back to the leasing company! We were asked to trial cleaning it with dry ice. We made a considerable improvement (and this was only a trial!) Eventually though the contaminant gets cold enough that the thermal shock effect stops working - and the other issue (as here) is that moisture from the atmosphere starts to condense on 'cleaned' metal - and the contaminant can start to stick again - possibly better than before!
It might be noted that the customer had asked for a free demo... and got one - the right hand side of this bobcat was cleaned - at some expense to us!
Metal / Machinery Cleaning
Degreasing of a Lathe capstan. Note that the capstan retains its chrome plating after cleaning - we can't achieve this with sand blasting
This (and the photo at the top of the page) are of us cleaning paint packing machinery a couple of years back. Over time paint had spilled onto the machine, and dry ice proved very effective at removing the product - the first time we tried it. However... a year later, we returned to clean the same machine a second time, and were much less successful! The reason was that the cleanliness of the first clean had left a very good surface for the paint to stick to... and it was stuck much better! So, for something like a machinery clean, it is worth considering a sacrificial layer of paint, varnish, or wax that can be applied post clean to provide a 'separation layer' in the future.
Dry Ice will remove anti-foul from GRP boats - and was found in this trial to be very effective at bursting Osmosis blisters! It isn't cheap though - although the fun of popping this number of blisters by hand made it worthwhile!
- A very 'clean' cleaning system. Cleaning chemicals / abrasives do not contaminate the work surfaces.
- It is not a chemical process so no noxious or harmful slurries or fumes are generated.
- The system is regularly used indoors, but good ventilation is required as the room fills with CO2
- Considerably less mess than other systems.