Day 11: Crossmember Replacement
After cleaning up the tubular crossmember it was obvious that it was rotted so badly, its structural integrity had been completely comprimised. Looking at it made me sick and I couldnt put the truck back together without addressing it. This post will be in a "how to" format, to aide others with this problem.
Materials Used:
1 1/4" Blackened Steel pipe, Has an OD just under 1 3/4" ($23 for 10 ft)
Welding wire ($5-10)
Tools used:
Dremel
Drill with 1 3/4" hole saw
Sawzall with metal blade
Chipping hammer + framing hammer
Not Shown:
Mig Welder
Angle grinder
Before you get overzealous and cut the old crossmember out, take some measurements of the gas tank bracket, so you will know exactly where it needs to be when you reinstall it. Try not to measure from welded edges as they will likely get cut when you are removing it from the old crossmember. This will save you alot of headaches later in the job.
Sawzall the crossmember off near the frame on both sides. You can see after I cut one side, the crossmember snapped just from me leaning on it.
Grind the pipe that goes through the frame down until you have solid metal all the way around. Clearance the inside of the pipe so that the blackened steel pipe will slide inside it. The hole saw proved ineffective, the dremel was helpful, but I found the best method was to use a chipping hammer or chisel, and then striking it with another hammer. An air chisel would probably be easier. Chipping off the scale inside the pipe will likely provide sufficient clearance. If you dont have scale, you probably dont need to replace the crossmember.
Now that the pipe is clearanced its a good idea to treat the rust, as you will not have another chance to do this. I stuffed a sponge saturated in eastwood fast etch and let it sit for an hour or so to attack the rust, then after it dried sprayed it with eastwood internal frame coating. I was very pleased with the results.
Now slide your new pipe through the old pipes going through the frame. If it is a tight fit, feel free to persuade it with a sledge hammer.
Weld your new crossmember into place. Weld all the way around the pipe on both the inside and outside of the frame on both sides. Trim excess pipe off the ends, otherwise you may have clearance issues with the rear tires.
Next cut the gas tank bracket off of the old crossmember. I used a grinder to do this, but it doesn't really matter how you do it, as long as you do not damage the bracket.
Using the measurements you took earlier, determine where the gas tank bracket must be. TACK weld the bracket in place. The welds should hold the bracket sturdy, but can be easily broken off with a few hammer blows. Keep in mind the new pipe is smaller, so try to maintain roughly an 1/8" gap between the bracket and pipe.
Now that the bracket is tacked in place, grab your gas tank and test fit it. Make sure all 6 bolt holes line up at the same time. If your measurements are good, you should be spot on. If not, make adjustments accordingly. Do not skip this step! If you weld the bracket completely then find out your measurements were off, you are going to have a major headache on your hands.
Now that you Have test fitted your gas tank, you can remove the tank and weld the bracket in place. I plan to coat the inside of the pipe with internal frame coating and paint the outside with rust encapsulator. Be sure to strip off the black with acetone before painting. I am heasitant to cap the ends of the pipe, as the old pipe was capped with rubber plugs and rotted from the inside out. If you do not cap the ends be sure to wash the pipe out with a hose from time to time.
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Day 12: Frame Painting
To prep for paint, I ran over everything again with a wire wheel, then wiped it down with acetone. FUN FACT: Acetone will eat through nitrile gloves! Be sure that your gloves are latex based. I figured this one out the hard way.
Before painting I coated the inside of the frame with Eastwood internal frame coat. I used three cans and was very pleased with the results. Its very messy so I reccomend you do it before painting the outside of the frame.
I laid down the first coat covering the underside of the frame, down the sides about an inch or so, and everything that I would struggle to paint after the frame is flipped over. The second coat I went over everything that was facing up or on the sides. (Essentially everything but the top side of the frame).
I let the paint dry overnight then flipped the frame over, wire wheeled and cleaned the top with acetone. Then painting, the first coat I covered anything that wasnt painted. The second coat I went over the top and sides. The end result was a minimum of 2 coats over everything. Its not perfect, but as good as you can expect to get. I am pleased with the results.
