Paint FAIL - 72" Mid Mount Mower restoration

[StrmChzr]

My 72" MMM restoration has dragged on for months despite it being a very simple straightforward project....72" mower deck has been on my 955 since bought new in 1995 and had no major issues except the back tires had rubbed the mower deck for 20+ years eventually resulting in holes.. soooo, I removed mower deck from tractor and had friend weld patches over holes and decided it'd be perfect time to sharpen the 3 blades and freshen up the paint - super easy, right?

Couldn't get 2 of the 3 blades off mower deck despite trying everything I could think of: entire can of PB Blaster soaked overnight, heated then doused w/ ice cold water, 3' cheater bar on ratchet.... finally a friend of a friend was willing to sharpen the 2 blades still on mower using grinder followed by fine grit belt sander to smooth up edge - blades look great so finally piece to puzzle was painting mower...

Thought paint prep would be fairly simple even if I didn't take the easy route of having mower deck sand blasted. To save couple hundred bucks, I instead spent several hours over course of few weeks using wire wheel on cordless drill to knock the rust "flakes" off deck.... I then power washed mower deck w/ soapy water (Dawn Platinum to be specific) and sanded deck w/ 100grit followed by 400grit sandpaper.. wiped deck down w/ denatured alcohol then sprayed 2 cans of Rustoleum primer on mower deck - just sprayed light coat of primer that went on really well and then waited couple days before beginning the actual final step of brushing on yellow paint...

I purchased quart of Majic Tractor, Truck, and Implement in John Deere yellow from TSC and spent few hours late one Saturday night brushing it on.... i essentially put two coats on, started on one side of mower deck and worked my way to other side than repeated painting process (which was all the paint in the quart container).... it looked really good (by tractor implement standards) not great but I was very pleased w/ how it looked... next day paint was still almost as tacky as it had been 18hrs prior, but I assumed the very high humidity was to blame so I left mower outside garage to "cook" for next couple days in the direct sunlight... a week went by and paint was no longer tacky at all but it was (and still is) very soft and almost scratchable w/ fingernail a month later!!!

Needless to say, I'm very disappointed w/ the paint job and need to redo it so I can reinstall MMM on tractor... any ideas what i did wrong w/ painting process? Even more important, what steps do I need to take to reprep mower deck and repaint to get better results???

I'm not looking for hot rod show quality paint, just something that'll dry hard and be resilient to normal wear and tear! Thanks in advance for any advice or insight into my Paint FAIL!

 

[Redlands Okie]

Paint FAIL - 72" Mid Mount Mower restoration

Is the paint your using oil base enamel or was it in two parts with a hardener ? Or something different ?

I ask because this info from the manufacture refers to a hardener. I wonder if you used it or the right amount ?

Also says to wait at least 24 hours between coats or till first coat is hard.

Sounds like it might still cure and get hard with time from what your saying and the info in the file.


Problem Solving:
• If the paint is not dry and/or the nish has wrinkled.
• Cause: Paint was applied too heavy and/or was not allowed to dry thoroughly between coats.
• Solution: Wait longer for the paint to dry. If the paint has wrinkled, the surface will have to be sanded.

http://www.majicpaints.com/wp-content/uploads/2013/08/Paint-Training_TSCWEB.pdf

 

[ray66v]

You are using industrial (alkyd) enamel. The reason that it is the least expensive paint you can buy, is because among other things, it has the cheapest solvents you can buy in it. For that reason it is very slow drying, and takes months to reach full cure. Which happens when all the solvents have evaporated.

You can do decent paint jobs with it. But, if you don't do it properly, you get little more than some corrosion protection.

I have not used Majic brand, but everyone here is pretty unanimous that it is very poor quality paint.

I would suggest spending more money, (aprox 3-4x as much), and use a low end automotive single stage paint, unless it's something you really don't care about, like a plow.

Here are some tips to using industrial enamel:

Use Rustoleum, Valspar, or Sherwin Williams brand.

Reduce it as little as possible when spraying. Use naphtha, or mineral spirits only. Naphtha will dry a little dry faster. The more solvent you add, the slower it will reach full cure. So, only use enough to make it spray nice.

Do not apply heavy, or multiple coats. This traps solvent. Trapped solvent keeps the film soft. And, reduces gloss.

Waiting up to an hour between coats may be necessary. You want to allow as much solvent to evaporate as possible. When it is starting to set up, (tacky, but not wet), you are ready top go. If you can, paint it in the sun, this greatly speeds things up.

You can add the proper amount, of the appropriate hardener. This will speed up the cure time, and increase gloss. Contrary to popular belief, hardener does not make it significantly harder in the end, it just gets the paint to full cure faster.

More hardener, does NOT make it harder, or cure faster. It actually will do the opposite. These chemicals cross link together on a molecular level. For everyone there to be happy, there needs to be the correct ratio of "hookers and sailors in a bar". Be sure to measure accurately.

Put it in the sun. The sun is your best friend. It will eventually drive out the solvents, and then the film will cure. Allow up to two months.

I have baked, (force dried), Rustoleum, (without hardener), in my paint booth, to a good hard finish. But, it took about 10 hours total at 165F, to get all the solvents out.

Whether, spraying or brushing, using hardener or not, these products contain many harmful, toxic chemicals. A paint respirator, and gloves, at minimum should be used.

 

[kennyd]

I've never read much good about the newer TSC "Magic" paint, they used carried Valspar and that was good stuff.

 

[kennyd]

Use Rustoleum, Valspar, or Sherwin Williams brand.

OR the OEM John Deere stuff, it is expensive but its really good paint.

 

[Snobdds]

I've always have used ppg epoxy primer and John Deere industrial black on stuff I want to last. The John Deere dries so hard, which I like.

 

[TractorGuy]

Never tried the Magic paint. Even Rustoleum will remain tacky and soft if applied at the wrong temperature and humidity. I did my 855 with rattle cans of Rustoleum farm equipment paint and it came out great.

Also you have to make sure the primer and paint are compatible. Even using the same brand products doesn't insure that. I was re doing my front door a while back and when I stripped it I saw it was galvanized. I had Rustoleum 2x paint and Rustoleum auto primer. I called Rustoleum and was told I needed their all metal primer. Back to the store to get two cans of that and all went pretty well. I had painted this door with oil base Rustoleum a few years back and the paint cracked and peeled. Paint wasn't compatible with the original finish.