A few years ago, I had too many diamond polishing jobs going so I rented a propane-powered planetary polisher to leave on another job. I left the machine with the guys and returned about 3 hours later. The project was like 3000 SF of dried yellow carpet mastic. I was impressed at how much they had gotten done with the propane-powered machine. Seemed like two times faster.
At this point since 2005, I have always owned electric machines either running off 220 or 480 power. This involves either “pig tailing’ to a panel or bringing a generator to run the concrete grinding machine.
I have never been too thrilled about wiring directly into a live high voltage panel, so I always made sure that, I was present at the start of every project to wire the machine. If you do this, you know this takes time to set up, owners & GCs (GENERAL CONTRACTOR), electricians many times freak out when you start pulling a panel. It is obviously extremely dangerous to have a concrete surfaces contractor messing with a panel.
The more I thought about the idea of propane diamond grinding machines the more I convinced myself that this could create an efficiency that I have not tapped into yet.
My thoughts were that with propane floor polishers I could:
- create a safer job environment and eliminate the electrocution hazard
- Free me from showing up on day one of job, no wiring
- I did not need a generator or a rental (one truck)
- No more cords
- I felt I could get better production time, and regain lost set up time
So, I sold all my electric planetary grinders and replaced them with propane-powered ones. Let me share with you some of my experiences with this change.
Propane
Buying these machines requires that you create a system for propane. You cannot just have one tank for one machine. You need like 5 tanks per machine. You do not want to make a ‘propane run’ with less than 10 tanks. Obviously, there is an expense to this beyond fuel for a generator. Lower steps burn propane faster than higher steps.
Maintenace
Propane concrete floor grinder machines have an engine on them so they vibrate more vigorously than electric floor grinding. This vibration creates more wear a lot faster on the machine, its grinding discs, and everything else. For reference, I had one electric planetary that only broke a few belts (not gear driven)and finally needed a main bearing after a decade of use with minimal maintenance. You can get away with very little maintenance with electric machines. Maybe like 20 times less.
Propane polisher grinder machines need constant maintenance and adjusting. Some of these machines recommend an oil change every 30-50-100 hrs. We could put 30 hours on a machine in 2.5-3 days. The tension on the chain is critical. We busted 2 chains in the first year. If your chain tension is off, you will burn through belts like crazy. We also burnt through clutches and bearings fast. On one machine we put $4,000 in just parts by rebuilding it that first year. (outside of engine costs)
Carbon monoxide
Another crucial factor that is not really talked about is the engines are useless after about 1000 hours. In fact, there is a sticker on the side of these machines that warn after 1000 hours these engines are beyond the useful life with regards to emissions and carbon monoxide output. I noticed this in the user manual after spending countless hours wrenching on the machines. It became a major problem. Carbon monoxide can kill an operator without their knowledge.
After a carbon monoxide situation, I spoke with a senior representative from our manufacture and warned him, “These machines are going to kill someone, it is only a matter of time.” He had some good suggestions about adding secondary CO sensors. He also shared with me his knowledge of a large propane burnisher company discontinued a whole line because of the liability created from an incident.
So, in my quest to create a Jobsite free from the dangers of electrical shock, we exchanged it for the dangers of carbon monoxide poisoning or potential hazards of that.
Another issue is that these machines should not be operated in small rooms due to heat & CO. Glue removal causes these machines to work overtime and will create CO engine exhaust with an engine that is not past its useful life. Create ventilation.
If anyone gets a hint that something is wrong with a machine or if a sensor goes off, it should be loaded on the truck and brought back to the warehouse for maintenance.
New Engines
To overcome this issue, we now have the policy that these engines must be swapped out every 1000 hrs. Now if you buy these from the machine vendor you are looking at $4-5K. Keep in mind that I can hit 1000 machine hours in like 6 months on a good run. We currently buy these engines directly and get them for $1,600-$2000.
In conclusion,
If I would have known all this ahead of time, I may not have made the change. If I can keep these machines safe, I can justify these costs. I still appreciate the mobility you can get from a propane-powered planetary. But either way, the entire industry has a responsibility to educate polishing concrete operators of the new unique dangers and added maintenace associated with these machines.
This review does not get into issues of dust control or diamond tools. You can read other reviews to look at single head or single disc polisher tools vs swirl-free types planetary.