Rust Repair the Right Way

[89 MJ]

I will be using various pictures from my build thread on my blue truck to give a little tutorial on how to properly do rust repair. Even if you are familiar with rust repair, I have picked up on a few tips from my dad (restores cars professionally) that may make your life a little bit easier. Now, I have access to a lot of higher end restoration tools, but I recommend that you purchase some of these as well, lots of these can be picked up at Harbor Freight or second hand for relatively cheap. We will start this with a list of tools that you will want:

1. Sandblaster

2. Drill with 1/8th inch and 5/16th inch drill bits-You do NOT need spot weld drilling bits

3. Cut off wheel (1/8th inch disc) (pneumatic)

4. Cut off wheel (1/4th inch disc) (pneumatic)

5. 90 degree grinder with 36 grit (pneumatic)

6. Air saw (pneumatic)

9. Blow gun (obviously pneumatic)

10. Various body hammers

11. C-clamps

12. sheet metal brake (not necessary, but very helpful when making 1 off patches, otherwise you could use a bench vise and freehand bend)

13. Welder (duh)

14. Vice grips

15. Weld through primer

 

Your first step is to identify your rust/metal that is going to get replaced.

 

Next up you will want to cut out your rust. It is a good rule of thumb to go 1" to 1.5" greater than your rust holes-the rust is always worse on the inside. Once you get that cut out, sandblast and use the weld through primer on the parts that you will keep.

 

3rd, you will want to trim your patch panel close to shape-leave it a little on the larger side, you don't want to make a patch twice  

 

Once you get your patches made, start trimming out the metal (not the patch metal, the original truck metal) with the air saw. Only go an inch or two at a time and use tack welds to hold it after you cut it out. Try to make the corners of your patches round to distribute the heat and prevent warpage.

 

Once you get your new patch tacked in, continue using small tacks when welding in sheetmetal. If you lay a solid bead, you will warp your panel. Move around on the panel when you are tacking it together and use your blowgun to cool the metal after welding it.

 

Use your wider cut off wheel to knock down your welds, don't make them flush, just take 80% off of the weld. Smooth them out with your 90 degree grinder. 

 

When you are happy with how smooth your welds are, sandblast where you have welded. Be sure to be careful with your blaster, it is easy to warp the metal. Sandblasting the metal will find any pinholes in your welding, you will need to make sure there are no pinholes.

 

Then you are ready for primer and body work.

[89 MJ]

When it comes to drilling spot welds, we have found that if you go through both layers of metal with a 1/8th inch drill bit, then go through just the layer you are wanting to replace with a 5/16th inch drill bit, it will actually work out better than using a spot weld drill bit. After drilling through it, the metal will just about pop off.

[PhilisDiller]

Thanks for the great writeup!  This is perfect as I've been getting ready to look into repairing my rust once the motor is happy

[89 MJ]

1 hour ago, PhilisDiller said:

Thanks for the great writeup!  This is perfect as I've been getting ready to look into repairing my rust once the motor is happy

Glad I could help!  

[Tex06]

On 1/19/2021 at 10:48 AM, 89 MJ said:

 

 

Once you get your patches made, start trimming out the metal (not the patch metal, the original truck metal) with the air saw. Only go an inch or two at a time and use tack welds to hold it after you cut it out. Try to make the corners of your patches round to distribute the heat and prevent warpage.

 

Ok, question on this part. Making my patches (either by hand or from a preformed piece) is always my biggest struggle. Are you saying that you tack the patch panel in place in a corner, cut a little out with the air saw, then put another tack weld?  Basically cut, tack, cut, tack....all the way around? Does the tacked in patch get in the way of the air saw?

Sorry for all the questions, I've been doing body work for a few years but I've never heard of this method. If this is faster than my current way of tin snips and files.....heck, I'm all for it.

[89 MJ]

53 minutes ago, Tex06 said:

Ok, question on this part. Making my patches (either by hand or from a preformed piece) is always my biggest struggle. Are you saying that you tack the patch panel in place in a corner, cut a little out with the air saw, then put another tack weld?  Basically cut, tack, cut, tack....all the way around? Does the tacked in patch get in the way of the air saw?

Sorry for all the questions, I've been doing body work for a few years but I've never heard of this method. If this is faster than my current way of tin snips and files.....heck, I'm all for it.

The tacked panel does not get in the way of the air saw. You want it so the blade is riding right next to it, this leaves a little gap for the weld to penetrate. You could go cut, tack, cut, tack, but you must make sure that you can get the cut piece out. I’d recommend cutting the tacks off once you have the trimming done in order to get the trimmed metal out.

[ExpatMJGuy]

I know these seems really basic, but is there anybody in the south within driving distance of Atlanta that has the time or ability to teach me the basics of welding and body work like this?  I'm SERIOUS.  I mean I have no problem paying for cost of materials and stuff, but it's frustrating.  I went to Universal Technical Institute (UTI) yes, the same one you see advertised on Motortrend and I don't know the first thing about welding.  I'm a great dealership mechanic because that's what I was taught.  I can accurately diagnose drivability, do alignments, find bad sensors, and I'm really good at electrical work, but can't tell you the first thing on how to put two pieces of metal together.  

 

Now to be fair, I went to the Charlotte Campus of NASCAR tech, and I could have taken NASCAR fabrication, and looking back to an extent I wish I had.  But when I was young I said, "unless I stay in Charlotte and work for a race team that won't be applicable to my daily job."  And it's true... Until I get home and decide to work on stuff like this.  Should I have paid thousands of dollars to learn to fabricate like that for something I only seem to do on my own time?  I was a mechanic later in the army and got to skip AIT because I had a civilian degree in Automotive Technology and never touched a welder even though we had them on our recovery vehicles.  Why?  Because we had other people that knew how to do it when the need came up oh so very rarely.  And when it always did come up, we just needed to get it done so someone else did it and, not play with teaching me.  I mean 8 years of being a mechanic in the army and it only came up a couple times.

 

Today it's a sore spot and a point of frustration.  I spent THOUSANDS OF DOLLARS to go to school and I don't know how to do this!  13 years later I am just now seeing the light to pay off that school!  Why the hell couldn't they give us one 3 week chunk of basic metal work instruction?!?  I don't want to be a professional welder.  I just want to be able to do basic repair work like this! 

[89 MJ]

2 hours ago, ExpatMJGuy said:

I know these seems really basic, but is there anybody in the south within driving distance of Atlanta that has the time or ability to teach me the basics of welding and body work like this?  I'm SERIOUS.  I mean I have no problem paying for cost of materials and stuff, but it's frustrating.  

If you can't find someone to come to you, you can PM me or I can send you my number in the PMs and I will help you through it. It may even be beneficial to post your specific spots of rust here in the forum.

What rust does your truck have that needs to be repaired?

[ExpatMJGuy]

14 minutes ago, 89 MJ said:

If you can't find someone to come to you, you can PM me or I can send you my number in the PMs and I will help you through it. It may even be beneficial to post your specific spots of rust here in the forum.

What rust does your truck have that needs to be repaired?

At this exact minute I don’t need to do this exact work on the body yet, because I’ve avoided it at ALL cost.  When I was younger, I even gave up and parted an XJ that needed floor pans.  Most northerners would have laughed at the fact I gave that car up over a couple holes the size of a quarter.  I simply gave up on that Jeep because I didn’t know how to weld.  That simple.  
 

But, I’m having some seats brackets made.  (Because I can’t effing fabricate)  I’m not sure a simple bolt  will work in the spot that the seat tracks tie into the bottom bracket.  That might be coming and I’m Leary.  Not only cause I have to fabricate another piece but it needs to look stock as possible for future inspections.

 

 In general not knowing how to do it limits me and my projects.  I don’t like being confined like this.  I’m upset that I didn’t even play with welders in the army.  But there was never time.  If I wasn’t turning a wrench in the motor pool there was always something going on.  Ranges, airborne jumps, online trainings that needed done, training meetings, safety briefs, formations, NCO schools, always SOMETHING.  I hate I missed opportunities.  And I hate that I just don’t know it.

[fiatslug87]

@ExpatMJGuy look at your local community colleges, I took a welding course there just for the fun of it. Learned everything from oxy-acetylene to TIG, not saying I’m proficient but I know the basics.

[ExpatMJGuy]

1 hour ago, fiatslug87 said:

@ExpatMJGuy look at your local community colleges, I took a welding course there just for the fun of it. Learned everything from oxy-acetylene to TIG, not saying I’m proficient but I know the basics.

@fiatslug87how much did a course like this run you and how long was this course?  I've very briefly looked at courses, but places are getting hard into pumping out professional welders that do it for a carrier and most of the results come up for that.  I can probably look more specifically on local community college sites and not within the search engine.  Again, at this stage I don't want that.  I just want to know the basics.  I've started watching some youtube videos, and I know much if it is trial and error, but I feel getting a real feel from somebody that knows what they are doing is helpful.  Things I won't know such as poor hand technique, or I've got settings on the welder wrong.  Getting a feel for things before I buy my own gear is also useful.  Hate the idea of buying crap gear cause I just didn't have the first clue when I bought it.  

[fiatslug87]

@ExpatMJGuyWell that was like 10-12 years ago (yes I’m old), I think it was a two unit class and cost roughly $50 which was more than normal because I already had a BS degree. It ran the full quarter and was two hours twice a week.

[ExpatMJGuy]

2 hours ago, fiatslug87 said:

@ExpatMJGuyWell that was like 10-12 years ago (yes I’m old), I think it was a two unit class and cost roughly $50 which was more than normal because I already had a BS degree. It ran the full quarter and was two hours twice a week.

@fiatslug87Sounds like you took that class when I was on my hiatus from the army and got my automotive degree.  Cause yeah, I’m that old too.  Graduated in 09.  Was signal in the army before that.  I had just graduated high school and joined right after 9/11.  Took a 4 year hiatus and went to school, worked for Ford and Nissan.  Economy was really sucking in that time frame so after a few years of struggling went back to the army but as a mechanic because I was just trained for That and my original carrier field was being phased out.

[89 MJ]

8 hours ago, ExpatMJGuy said:

In general not knowing how to do it limits me and my projects.  I don’t like being confined like this.  I’m upset that I didn’t even play with welders in the army.  But there was never time.  If I wasn’t turning a wrench in the motor pool there was always something going on.  Ranges, airborne jumps, online trainings that needed done, training meetings, safety briefs, formations, NCO schools, always SOMETHING.  I hate I missed opportunities.  And I hate that I just don’t know it.

We’ll get you through it. We will all just have to be patient, and you will have to be a good grinder.

[ExpatMJGuy]

9 hours ago, 89 MJ said:

We’ll get you through it. We will all just have to be patient, and you will have to be a good grinder.

Now one thing I’m good at is using a Dremel, wiz wheel, and sawzall!  That’s where my fab skills end. 

[scguy]

9 hours ago, 89 MJ said:

We’ll get you through it. We will all just have to be patient, and you will have to be a good grinder.

My ignorance showing, but what's better about a good grinder? I took a welding class in high school like 12 years ago, but it was basically useless for any automotive welding applications. We were welding trailers, so 1/4" or thicker steel. I try to weld anything now and I just burn though

[89 MJ]

9 hours ago, scguy said:

My ignorance showing, but what's better about a good grinder? I took a welding class in high school like 12 years ago, but it was basically useless for any automotive welding applications. We were welding trailers, so 1/4" or thicker steel. I try to weld anything now and I just burn though

He will need to be a good grinder to make his welds look good, more than likely. He will also have to grind the welds smooth if they are on the body. 

[Tex06]

On 1/28/2022 at 11:50 AM, ExpatMJGuy said:

I know these seems really basic, but is there anybody in the south within driving distance of Atlanta that has the time or ability to teach me the basics of welding and body work like this?  I'm SERIOUS.  I mean I have no problem paying for cost of materials and stuff, but it's frustrating.  I went to Universal Technical Institute (UTI) yes, the same one you see advertised on Motortrend and I don't know the first thing about welding.  I'm a great dealership mechanic because that's what I was taught.  I can accurately diagnose drivability, do alignments, find bad sensors, and I'm really good at electrical work, but can't tell you the first thing on how to put two pieces of metal together.  

 

Now to be fair, I went to the Charlotte Campus of NASCAR tech, and I could have taken NASCAR fabrication, and looking back to an extent I wish I had.  But when I was young I said, "unless I stay in Charlotte and work for a race team that won't be applicable to my daily job."  And it's true... Until I get home and decide to work on stuff like this.  Should I have paid thousands of dollars to learn to fabricate like that for something I only seem to do on my own time?  I was a mechanic later in the army and got to skip AIT because I had a civilian degree in Automotive Technology and never touched a welder even though we had them on our recovery vehicles.  Why?  Because we had other people that knew how to do it when the need came up oh so very rarely.  And when it always did come up, we just needed to get it done so someone else did it and, not play with teaching me.  I mean 8 years of being a mechanic in the army and it only came up a couple times.

 

Today it's a sore spot and a point of frustration.  I spent THOUSANDS OF DOLLARS to go to school and I don't know how to do this!  13 years later I am just now seeing the light to pay off that school!  Why the hell couldn't they give us one 3 week chunk of basic metal work instruction?!?  I don't want to be a professional welder.  I just want to be able to do basic repair work like this! 

Yo....is Snellville too far?

[ExpatMJGuy]

12 minutes ago, Tex06 said:

Yo....is Snellville too far?

No I live in Buford.