M101A1 Undercoating Removal, Paint Prep, and Painting

Bought my first M101A1 and I am working on redoing the wiring, busting rust, and painting it with the help of my brother-in-law. I will post some more pictures of the progress when I can download them from my camera. I pulled off the bed to get better access to the underside of the bed and the frame to remove the rust and get some primer on it. I am going to paint it with the Rapco Parts Gillespie Desert Tan 686 Paint. I started grinding off the dirt and grime and paint off the bottom of the bed and saw that the undercoating is very thick and seems impossible to get off without a whole lot of industrial strength degreaser. Either the road tar has built up on it for a lot of years or they coated it with asphalt tar to protect the metal, but it is very thick. I am wondering if it is worth taking off and if maybe I should just put a new coat of undercoat over it (If so, what product do I use and where would I get the product). Any recommendations on how to get this off and your experiences with paint prep and painting are welcomed as I am new to this. The frame of the bed has a lot of rust down inside and I was wondering what you would recommend to put down in there and how to put it down in there to stop the rusting as well. Thank you for your help.

Welcome the the forum. Could you post some pics of the" road grime?" POR is good for stopping rust! You might powerwash the trailer and see if that will be of any benefit.

M101A1 Project progress pictures

Thank you for your recommendations Ripcord01. I have posted some pictures of the M101A1 Project. The last picture shows the undercoating or road grime on the bottom of the bed - the black area on the upper right of the bottom of the bed is where I grinded on it and the black you see is the thick tar. Any suggestions on how to deal with this in preparing for painting the bed? And should I apply some product to seal the bottom of the bed and the frame up from further corrosion or just paint it? Thank you for your help.

Sight unseen have you tried using a 5 in 1 and see if you can scrape any off? Mineral spirits, wear gloves and a mask,. Since you got the bed off already you might ask around and see if anyone has a better bed for your trailer..seemslike that would be the best solution, not knowing what the actual grime even is. ..

Preasure wash it, then scrap off any loose stuff. From there you can either use ruberised undercoating or bed liner. Bed liner cost more but will protect it the longest and most likely adhear to what is already there. Plus I would use the bed liner on the inside of the bed anyway. The main thing is to start with a clean surface.