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John, I am not a good one to give you an idea on the quantity. I always go on the heavy side to the extreme because of my work flow. I use a 2-part product for everything. They all have a pot life and any unused quantity mixed has to be thrown away after one to 8 hours, depending on product. My work flow is slooooow. I do everything piecemeal at different times. After 2 years I still have the fenders and most of the cast to do on my AC-B :o). That means that I have an abnormally high amount of waste since I always mix up a bit more than I think I need so as not to run short on any step. Sometimes I overestimate the amount needed and have quite a bit left over that has to be thrown away. I also use non-hvlp equipment for the most part which (admittedly) tends to cause more waste. Since you are not using hardeners in your surfacer and topcoat, you will not have the pot life issue as a problem to deal with. You can save any mixed but unused material in a tightly covered container for use at a later time if desired. You will need to consider this matter on the epoxy primer however. That's not so critical since you can stop and go buy more if you need to. You may not have that luxury with the topcoat, even with no hardener. The topcoat should go on in a continuous series of steps with only short flash times between the first and last coats. If you are doing things piecemeal at different times (days), you can keep track of usage as you go and buy more as needed, continuously estimating ahead based on past usage. If you are trying to do much, if not all of it in one day, then the situation changes. If you don't have enough material on hand to complete all coats for that work session, you'll kick yourself later. Having to buy full gallons at a time is not particularly effective for a small user on a one-shot deal with an unclear total end use quantity. Being able to buy material in quarts, even if more expensive on that basis, I think is a better way to proceed. I pretty much agree with CNKS except if you must plan and buy all your materials at once I would be a little nervous with the 2 qts of each color. You might make it and you might not. A full gallon (of each) would be too much but 2 qts is cutting it a little close IMO. You would be OK with his procedures and you probably would not be OK with mine. I'll try and refine some numbers so bear with me. When you compare quantities of materials or costs, be sure to do it on an "after mixing" or RTS (ready-to-spray) basis. Also try to estimate the number of coats you will need. You can usually go by the tech sheets on this. Here's an example: The OMNI MP170/175 epoxy primer is mixed 2:1. That means that 2 parts (by volume) of MP170 primer is mixed with 1 part (by volume) of MP175 catalyst. Therefore 1 gallon of MP170 results in 6 qts of RTS material. The tech sheet calls for 1 coat (I usually use 2 but I don't think it is really necessary). Six qts at 1 coat goes a long way; 845 square feet if no waste per the tech sheet (563 sf/gal rts at 1 mil). Whoever is trying to sell you a gal of catalyst to go with a gal of MP170 either doesn't know the product he is selling, doesn't care or is trying to pump up the price in favor of another product. I noticed that the EPX900/901 is mixed 1:1 which would yield a full 2 gal of RTS material. Sounds like more doesn't it (8 qts vs 6 qts)? But it's not. It's actually less! It is not clear on the tech sheet but it appears that 1 coat is also the recommended build for the EPX product. The stated coverage is actually significantly less than the MP170 for the same amount of material (no loss = 396 sf/gal rts at 1 mil or ~800sf for 2 gal rts). The only reason I can think of for this is that the EPX has significantly more volatile material in it than the MP. Even assuming an average total efficiency of 25% this is still 200 sf for either the EPX or the MP, likely more than you would use on a typical tractor. I don't know about the MP170 itself but do know the 175 catalyst is available in qts since that is the way I have bought it. A similar exercise can be conducted with the topcoat. OMNI MAE is reduced 4:1 with the appropriate MR reducer so 2 qts of MAE winds up to be 2-1/2 qts of RTS material. You should plan on 3 coats for this per the tech sheet. The coverage for RTS MAE is stated as about 500 sf per gal per coat (1 mil). Therefore, with no loss, 2-1/2 qts RTS at 1 coat should cover 312 sf (2.5x500/4). Three coats would cover 100 sf w/o loss. Assuming an average of 30% transfer efficiency for non-hvlp and another 5% for misc loss (25% total efficiency), that means 2 qts of MAE color (2-1/2 qts RTS) would cover about 25 square feet with three coats. You may do better than that but I wouldn't bet on it. You'll have to decide if 25 sf is enough for each of the colors and plan accordingly. Don't forget that a full sized non-hvlp gun used on individual small parts will result in terrible transfer efficiency. To put this in some perspective, I have to date used between 2-1/2 and 3 qts of MTK color out of a 1 gal can on my AC-B. The mix ratio is more favorable than the MAE (4:2 rather than 4:1). I am using 3 coats. The tractor is not half done and the B is a small tractor. The 1 gal I started with will never finish it. That's poor, I know, but is the result of the materials and equipment I use and the nature of my work flow. Most will do better than that; perhaps a lot better than that. Just goes to show you that estimating quantities for others with many variables involved can be fraught with problems, which is why I try to avoid it :o). The quantity of surfacer required can be highly variable depending on how smooth the surface is to begin with. Don't expect too much from it. It is nothing but a little more heavily bodied material that is formulated for easy sanding. It is intended for filling fairly minor sandscratches only. Do not try to use it for any other purpose. The heavier the sandscratches, the more material is going to be needed. It will take more to fill 80 grit scratches than to fill 180 or 220 grit scratches. I have used as many as six coats of a surfacer before. Remember that most of it will be sanded off prior to topcoating. The tech sheet for the 181 says 2-4 coats over a 180 grit prep. One thing about the 181 is that it is reduced 1:1 with the same reducer (MR) that is used in the MAE topcoat, thereby eliminating having to buy different reducers. One thing I ran across in buying the 181 once quite a while back is that the supplier would not sell me the MR reducer at the same time I bought the 181...due to environmental VOC emissions rules in my area. He would only sell me the MS250 which, I think, is nothing more than acetone (an exempt solvent). The tech sheet still calls for and permits use of MR and I would have no problem using it, although it might be illegal to do so in my area. Not sure this all helps you any but is provided as some food for thought. I suspect your eyes may be glassing over but I have attempted to put some numbers to your unique situation. Is the OMNI system worth 2-1/2 times the cost of the Commercial system? Perhaps not. It is worth more. How much more is the subject of some debate. I am just not convinced the prices/quantities given represent a true apples-to-apples comparison. I have no problem with the 190 cleaner. I have never used it but it is covered in the OMNI tech sheets and I am confident it will work fine instead of the DX330. I use the DX330 simply because I bought 2 gal of it years ago. I will never have to buy any more cleaner. A gal of the 190 will probably last you for years to come. You don't need much of it for any single job. Too bad they don't sell it in pints.  Rod
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