The reason I am bringing this up is that recently I ran across a product (which I will not name for the moment), I am not trying to promote them). This company makes customized stop leak material that works on most everything automotive including open drive car AC systems, all common refrigerants No downsides. 96% + success rate I learned that chemistry has come a long way. Think about it. Who believed in 1960 that there was a genuine product on the market which could truly and permantly plug a leaking head gasket in a car ? Here is my point: I think geo manufacturers and the heat exchange coil makers need to spend a few more dollars either perfecting or testing possible leak sealers on the market. Just because some past ones did not get along well with compressors doesn't mean the challenges cannot be solved. If you do not want to test new units, at least test the stuff on used ones. The product I just mentioned can seal a head gasket in one hour of running. I was told the chemistry detects pressure difference and the product seals at the pressure difference without reacting negatively with anything else: antifreeze, water, etc. If this can be done for cars and if the product I am describing can hold up to combustion pressures, I just don't believe that we are that far away from refrigerant / or water side leak sealers that can search out a leak and plug it. There is one other way to look at it. Test the stuff first, but imagine the selling point !
HVAC: I am always looking for ways to seal leaks. Big ones are easy. The very small one make you crazy and take up tons of time trying to find them. What have you got? Send me a PM if needed. Mark
How do I reply privately ? I am interested in promoting discussion, not selling something. I can tell you this. There are some smart chemists out there. Chemistry models are tested first with computer modeling. I know a guy that works at Savanna nuclear. There are super glues out there that work on nuclear stuff at nuclear temperatures. A man in my state perfected some formula which stops storage dry rot on automobile tires. He is going to become a multi millionaire because dry rot does not flatter the manufacturer of the tire. I have an old 1987 Astro that developed a head gasket leak last november. I fixed it with $60.00 dollars of pour in chemical. NOTHING in the engine itself was taken apart.
I worked on cars for many years and did more than my share of automotive AC work. I owned a kit for deternining if an ac system was contaminated with stop leak sealer. I also had a refrigerant identifier as there were a lot of "the next new thing" refrigerant mixes that were being used on cars by people who didn't know what they were doing. Since we were required by law to recycle refrigerant, if I detected sealer or contaminants, that AC system did not get connected to any equipment of mine. It wasn't worth contaminating my equipment, and any AC system I worked on afterwards. Some of the larger AC shops I knew, would maintain a junk reclaiming system, where the contaminated refrigerant would be sent on to a disposal center (for a pretty good fee to the customer). I would hope that the HVAC pros out there would have similar standards, especially if they came to my house and worked on my HVAC system. As far as head gaskets go, there's no free lunch. I no longer am in the automotive business, but if one of my vehicles needed head gasket work, I'd tear it down and do it right. FWIW, at least on cars, dye and a black light worked quite well to find the smaller leaks. The 2 cents of an ex automotive tech.
In November 2012 I was preparing to have my 1987 Chevy Astro towed to the junkyard as scrap. The product I used to repair the leaking head gasket immediately made the car totally drivable. It cost $60.00. As of this date the Chevy Astro is totally usable. I was not kidding about my friend at Savanna Nuclear in South Carolina talking about super glue used there or the person who has a formula which ends "dry rot" in automobile tires. Just because you used a bad product 5 or 10 years ago does not negate the progress made in chemistry. Read my earlier post. A man with an experience is never at the mercy of a man with an argument. Insult me a little more and I will name the product which is selling out right, left, and center. It is certainly true that we will have to carefully test all proposed products. Personally I am concerned about the negative attitude of most geo thermal manufacturers. But progress is progress. I think I have already said this at least two times, but it sounds to me like you do not know much about what is going on or changing in the industry.
You may be correct as I've been out of the automotive industry for the last several years, but I do keep up on the new developments. To the best of my knowledge, the use of sealants is still a warranty voider in automotive ac systems (dyes are not). Unless the OEM's were recommending a particular sealant's use I wouldn't use it myself...especially on a customer's car. It's a totally different scenario to try a product on a car that's destined for the junk yard, but when a customer is paying me to fix their car, it's done in a way that they get a quality repair and I limit my liability for come-back. As far as the HVAC industry goes, I have no idea what the manufacturers recommendations are concerning sealants. As a homeowner with a geo system, I would hope that the manufacturer made a system that doesn't leak and fail (it hasn't yet). If it does leak, I would hope that the guy who comes out to fix it can find the leak and repair the system without having to use a sealant, but if the manufacturer wants it done that way and stands behind it, so be it. BTW, no offense intended by my previous post...just giving the perspective from someone who has seen the results of the use of various sealant in cars, and had to bite when I saw your reference to cars.
==== You have pretty well summed it up. No professional on this forum is saying yet: go use this stuff. None of us would dare do anything to void our warranties, auto or home, which is why I think the manufacturers of AC systems and Copeland, Bristal, Mitsubishi et; al should do the main testing for us. The standard rules still apply for the moment: never open up a system except for quick immediate repair, never mix oils, store a system that cannot be repaired under vacuum or better, pressurized with DRY nitrogen. If we had a time machine and we brought back an auto mechanic from the 1920's and showed him engines operated by computers, front wheel drive, and 5-20-W oil, he would be amazed. Progress is made. I currently run a couple of large commercial centrifugal chillers which do not have one drop of oil in them. That is an example of thinking "outside of the box". Just because you couldn't build a centrifugal without oil in 1956 doesn't mean that we should keep on building them the same way because that's the way we have always done it. Just think of all the special purpose glues and lubricants that are on the market. Really unique stuff, chemistry marvels. I am saying not so much to you, but to the wider audience, let's think outside of the box.
Whatever it is would have to avoid considering a small hole with a big pressure drop (such as a metering device or reversing valve pilot cap tube) a "leak" and act to seal it. We in the field are unwilling to become R&D beta testers without serious motivation. You suggested compressor manufacturers shoulder the R&D burden. Why would they? Compressors don't leak, coils do. "Not our problem" would say compressor folks. In fact, compressor manufacturers have a strong disincentive to do diddly squat to help cheaply solve coil leaks...when a 8+ year old system develops a coil leak, chances are good the whole system gets replaced, and that equals a compressor sale. Repair a leaky older system = no compressor sale.
Well the ground hog was right and I am looking for things to do besides free rescue work. I use certain chemicals is hydonic systems. Conditioners and some leak finders and fixers. I have gotten the OK to add some of these products to geo systems. I have never had anyone ask for an MSDS. When I get an electronic refrigerant detector scream while re-purging a vapor locked loop with a loop cart, where is the leak? Not in the pond due to beavers liking to chew HDPE. Cut to the chase. What do you have? I'll chose who does the warranty repairs. It is not like the old days, the companies know when they make bad stuff and then stick the contractor for the repair. One gets what one pays for, always. Mark
================ Touchè, ya got me ! You have made some very good points. Nonetheless, IF american manufacturers are seriously trying for the WORLD market, external markets will not tolerate less than the highest, consistent standards of quality. It seems to me that current US problems are not generally in american made compressors (winding insulation issues were solved many years ago), (reversing valves occasionally stuck, so they opened clearances up .002), but in heat exchange coils and maybe a few safety devices. Can you imagine the Germans or the Japanese, and now the people of Brazil, buying anything that is not at least equal to their own quality ? (The Brazilians by the way, are now working on their first nuclear submarine). I once worked in France (before I trained in HVAC in the states) and I had a great German friend who fixed refrigeration in European supermarkets throughout Germany and France. He was VERY, VERY, VERY good. Thoroughly trained. He took me home one Christimas and showed me his father's "homemade" expirimental solar project, which worked. It was so complete with instrumentation I thought I was at a Carrier / Trane / York test site. I can't even begin to describe the gulf between German standards and ours. I got involved (through my work) in Japanese Slim Jim air to air type products by accident, but I can tell you this, they do not give any real problems unless overcharged, or hit directly by lightning or a car. I have yet to see one leak.
I wouldn't want to put words in manufacturers mouths, but it doesn't seem to me ours are designing for the world, at least at the resi level. Central duct systems are limited to North America, and the ductless units sold here by the majors seem to be rebadged Asians. The foregoing is off the cuff, not based on rigorous research.
The first generation stop leak I have seen at work in my AO was killing compressors. If it has improved......sweet. Whish I'd thought of stop leak when the Caravan we scrapped blew it's head gasket. Darn.
Area (of) operation. I could footnote, one colleague told me that he was adding a hard start cap with stop leak and enjoying some success.
Sometimes you see "sticky" refridgerator compressors, i.e; doesn't want to turn, on single phase residential. You will hear a loud "click" on the compressor overload (which is trying to save the compressor from burnout) If any rotating compressor shaft is in oil, it really should not bind up which is why I may add a little (of the correct) oil after changing a compressor on a system that has previously leaked. (Personally I'm not sure why a shaft that has been turning for 12 years on a compressor should become hard to turn if the system doesn't leak) Sometimes a start capacitor or potential relay kit may cure the startup problem, or extend life of the unit a couple of years. I have saved around 6 compressors where I work; (didn't get and $3,600 bonus though) If this stuff works at all, the fridge or whatever will start up perfectly the first time and each time after that. One of the reasons, by the way, you have to follow factory recommendations on refrigerant "changes" is that drop in refrigerants that are different from the original not only may require a different oil, the actual horsepower requirements could be different. For example imagine doing such a change and discovering that a 5% increase in horsepower is required. BURNOUT ! These are really "delicate" BECAUSE if the shaft is not turning, you are pulling lock rotor amps and you really shouldn't pull that ever for more than 2 seconds. Electrical failure will occur in seconds. So let me say this: if I thought a stop leak was affecting how a compressor started, or ran, I wouldn't go there ! Typically adding a hard start capacitor is not due to anything that anyone has done to say a refrigerator, or something else. Something has just changed in that compressor. Whether that is oil breakdown or something else, I can't say here. I'll defer to Copeland.
