Quick Update
Hello all,
It has been awhile since I wrote an update, about a month. It has been very busy for me lately with family, holidays, and had to go to Japan for 1 week for work. Over the Christmas holidays I did spend a significant amount of time trying out different sand blasters because I figure that is the best way to tackle the rust condition I have and I want to preserve the frame, cleanup the body and not have to do this again. I tried several units from princess auto, first with the little gravity feed hand held blasters, just didn't have enought power to remove the rust. Then stepped it up and was able to get their 10 gallon pot blaster on sale from $250 to $125. I tried 2 of them before giving up on those units. I found the crushed glass they sell at princess auto and recommend for it to pack up and you continously need to shake the unit as it clogs at the media valve. It is winter and I have an inline water trap so I don't think moisture is an issue. I think the inconsistent bead size makes it higher risk to packing. I then tried running bainite steel shot in it and it worked great for the first 10 mins however, then the hose filled up, which happens when pressure drops and normally is easy to relieve, however, when I tried to turn off the media valve it jammed, so I brought it back. I found a higher end unit at TSC stores for $179, and researched media for it, I was advised to use 80 grit aluminum oxide ($44 for 50lb bag at princess auto) and it works very well. I have to run in short bursts with my 2hp compressor and when you stop you need to shut off the media valve but it works very well.
I am working now on a recovery system for the aluminum oxide, it can be reused 100 times just need to capture and screen it. In order to avoid getting large rust particles in my recovered media, I decided to try and remove the thick large scale with a pneumatic needle descaler from princess auto ($39). This little tool is amazing. It goes through heavy scale like butter. It will not get it down to bare or clean metal but preps the surface great for sandblasting or sanding nicely. It is possible that with a product like rust bullet or POR15 you could just use the descaler and a little wire wheeling and then seal the rust in, however, I want to be sure I get rid of all the cancer. I have used it for 3 hrs straight now and have had no issues with it. You need to be careful when using it on thin sheet as it will warp and bend it the metal but with my condition, if it goes through it then the metal there needs to be replaced anyway so is good for finding the soft spots. It also breaks up thick bondo very well, especially if there is no structure behind the bondo or just mesh patch, breaks it right up and off. Anyone who is fighting heavy rust like I am this descaling tool is very handy and is a great first step at getting the scale off quick and getting a real good look at what you got to work with.
I am about half way through using the needle scale tool on the rear of the truck. I will post some pictures later of the results before I restart sandblasting again.
Cheers...