OMNI Hardener

I used MP170 epoxy primer under MTK acrylic urethane on the metal parts. Since both wood (oak) and a decal was involved in addition to metal, I clearcoated everything with MC161 urethane clear. The epoxy MP175 catalyst was approximately two years old and had been opened before on several occasions as long as two years ago. The hardener for both the MTK and the MC 160 was the slow hardener (MH168) since temperatures were in the high 70s. The MH 168 was also about two years old and had been opened and partially used similar to the epoxy catalyst. All products have also been through many freeze/thaw cycles since they have been kept in an unheated shop over two winters.

The label instructions for the MH168 say to use the entire contents within 14 days of first opening. Well, I am way past that :o). I didn't put any kind of inert gas in the air space during previous uses as some may do. Anyway, there did not appear to be any gelling of the contents remaining in the 1/4 full quart so I decided to try the stuff out. The hardener was fairly expensive ($26/qt) and I really didn't want to go buy more just for a small use and wind up wasting a lot.

It seems to have worked well even with the old catalyst and hardener. The films set up normally and today the parts have been reassembled. So if you have some old OMNI hardener that has not noticeably gelled and you are not using it in work-for-pay or especially important projects, go ahead and save some money and use it. I will not hesitate to do that again.

I would be interested in the experience of others along such lines. I have a can of PPG DXR80 hardener that is over 20 years old. That was (is) used with their Delstar AE. It has not been opened but seems to be in a liquid state. Anyone care to guess if it is still usable? I have an old gallon of Delstar black that is half full so I may try that out the next time I have a need for something black.

Rod

Well, I guess we just disagree about the OMNI. I have had excellent luck with it (MTK and MC). Same goes for the OMNI epoxy primer and their surfacer. I have only heard others complain about coverage with the OMNI MBC. I don't do bc/cc so that doesn't concern me. I find the MTK coverage to be very good. I typically use 3 coats but certainly could get by with the 2 minimum recommended on the tech sheet. That agrees nicely with the 3 coats recommended for the higher priced Centari AE and the 2-3 coats recommended for the higher priced Delstar AE. I also always used 3 coats when using either the Centari or the Delstar. So my own experience, although more limited with the OMNI, simply doesn't bear out the "twice as much paint" claim. Perhaps there could be an issue with coverage depending on color or uniformity of the substrate? I always put my color coat on a totally even-colored base, usually the grey epoxy or the grayish tan of the surfacer. My experience with the OMNI has been only with orange on both of those so I can't confirm good coverage with other topcoat colors or non-uniform substrates. I don't do metallics anymore so I can't address that possible factor either.

I also have not had a problem with drying that you mention. The MTK is always dry to the touch in just a few hours - no worse than others I have used, and the MC clear can be handled easily in a couple of hours. I simply have not had any problem or complaint at all with drying. Componding is not an issue with me either. I assume when you say polish that you really mean compounding. As Butch says, such a refinement in surface finish is not practical for most tractor work. Perhaps the hood and fenders maybe...but if you have to go to that effort to obtain an acceptable finish, you are either doing something wrong or you are treating a tractor like that Mercedes I occasionally bring up. Actually, I have seen some single stage non-compounded finishes that would be suitable for a Mercedes but then again maybe I please too easily.

Poor gloss retention? Well, I have one of my tractors outside that was done two years ago in MTK and the gloss and color shade is just as fine as the day it was sprayed. It is never housed so sees the NH weather outside continuously in all seasons. I'll have to reserve judgement for times exceeding two years but I guess I will find out if poor gloss retention (relatively) is a valid complaint.

Worst smell? I am not into siffing paints so I can't say :o). I don't recall it being any "worse" than Centari or Delstar. All the four or five different hardeners that I have had the displeasure of smelling have a rather obnoxious odor to them. Worse than the paint with no hardener. In any event, after mixing I am inside a fresh air mask so smell is not a factor for me.

As far as other manufacturers are concerned, I only have three available in my local area. DuPont, PPG and Martin Senour. I have no experience with the MS lines. My past intermittent experience over 30 years has been with DuPont's Centari and PPG's Delstar. I have been using OMNI, along with some Centari for the past two-three years. I have not tried the NASON line in DuPont. I guess I would have to have a future poor experience with the OMNI that I attributed to the paint for me to bother to try a different product line since I have a small investment in different temperature reducers and hardeners that are specific to it.

Thanks for your comments but I just can't agree with your "anybody but OMNI" putdown. I know the high-enders will look down on most "economy" lines as do the bc/cc crowd with AE. That's life and expected. I am pleased with OMNI for the price and have no reason yet to look elsewhere.

Rod

Thanks for the offer but I will pass at that price. My interest drops rapidly when the price much exceeds $100/ready-to-spray (RTS) gal.

You might look to DuPont's Centari AE for a replacement black if you haven't already tried any of it. Nice stuff, similar to Delstar in quality. The last time I bought some of that was about 3 yrs ago. I think the price was around $100 per RTS gal, maybe a little more. That was dark blue which is likely at the low end of the color price scale, similar to black. I have used it with a brush for painting a 3/8" chain and it seemed to work well enough. Sprays very well and is difficult to run. Nice flowout. It may go the way of Delstar before much longer. Not available in persian orange since the NASON line hit the street.

I have never tried the Bloxygen. I expect any dry inert gas would serve the purpose of keeping air out of the container and presumably prolong the safe usage time. I might try using argon. I have plenty of that on hand...just flow some into the can. It might also be that the 14 days is overly conservative for product liability reasons. I guess I'll find out for myself in the days ahead.

I have never tried adding a reducer to the MP182. I have not found it to be necessary. However, I am used to spraying quite wet coats anyway with non-hvlp equipment so I haven't noticed an issue with flowout. Seems fine to me w/o a reducer.