I'm redoing my F250 and I'm replacing my inner rocker panels along with everything else.My question is that I sand blasted my cab supports and even though its all clean what do you recomend I use to prevent rust on the bare metal before I use weld thru prime to coat the metal. Thanks in advance!!

Don't think you'd use anything before weld-through primer...unless I'm misunderstanding the question (?)

There are obviously different methods available so I will give you my perspective.
Whenever I sandblast metal the first thing I do is cover it with epoxy primer inside and out. Normally two coats and let it sit for at least 24 hours.
Clean the edges where welding will take place with a sanding disc on a 4 1/2" grinder.
At this point you can use weld thru primer on the edges and then position and weld your panel. Personally I rarely use weld thru primer anymore unless I have no access to back side of the welds. When my welds are completed (unless they are simulated plug welds) I run the grinder over them and then brush on epoxy primer to cover the welds front and back.

Will do and thanks for the response's.

'68 Coronet R/T wrote:There are obviously different methods available so I will give you my perspective.
Whenever I sandblast metal the first thing I do is cover it with epoxy primer inside and out. Normally two coats and let it sit for at least 24 hours.
Clean the edges where welding will take place with a sanding disc on a 4 1/2" grinder.
At this point you can use weld thru primer on the edges and then position and weld your panel. Personally I rarely use weld thru primer anymore unless I have no access to back side of the welds. When my welds are completed (unless they are simulated plug welds) I run the grinder over them and then brush on epoxy primer to cover the welds front and back.

I use Norton Blaze strip discs to remove epoxy primer, or I spot blast plug weld holes after epoxy. I'm not a fan of hogging off more material with sanding discs and a 4 1/2" grinder. I don't even use a 4 1/2" grinder unless it is for heavier steel work. Way too bulky of a tool to use when doing this work every day. Nothing wrong with a bulky grinder if your tool arsenal is not very large, and you are not aggressive with sanding and grit size. What is a simulated plug weld? A plug weld is a plug weld. Do you mean spot welds?

I do a great deal of late model truck rot repair and use panel adhesive where appropriate. Much faster and easier than welding. Since it seals the pinchwelds and flanges, you do not have to be concerned with epoxy or weld through primer. Make sure you coat the cavities after repair.

You are correct. Plug welds obviously would not be simulated.
I have only used the panel bond adhesive on a couple of small repairs. Are you using right over the epoxy primer?

'68 Coronet R/T wrote:You are correct. Plug welds obviously would not be simulated.
I have only used the panel bond adhesive on a couple of small repairs. Are you using right over the epoxy primer?

Nope. I'm following the TDS for my SEM adhesive. As with any adhesive, just read the instructions.