How to repair rust holes ?

[AMC86Kid]

My truck has one rust hole 

thankfully it’s not huge 

I say around 3-4 inches 

 

how do you guys recommend this to be fixed ?

[JMO413]

Pull the seat and carpet and weld in new metal. 

[89 MJ]

46 minutes ago, JMO413 said:

Pull the seat and carpet and weld in new metal. 

This, but I’m also going to recommend butt welding it. It will prevent moisture from getting between layers causing rust. 

[Minuit]

And if there's that, there's likely to be more. The job ain't finished until you know there's no more rust. That means doing surgery beyond just cutting out the obvious rust.

[Dzimm]

Yeah I'd cut that upper layer out to see what's under it.  Through that hole it looks to have more rust and the underside of where you've hit with the grinder will be rusty.

 

[phatton]

What part of the truck is the picture showing?  The metal under the hole is a big concern - you're pic shows it to be very rusty.  That area needs to be addressed before you patch the hole.  I would cut a strip off the top piece of sheetmetal wide and long enough to expose the rusty section underneath, patch that section first and the fab a top patch.  This repair work requires a welder and metal shaping skills.

[AMC86Kid]

It’s the floor on the passenger side

[89 MJ]

32 minutes ago, AMC86Kid said:

It’s the floor on the passenger side

Just knowing it is the floor tell me that there is more rust than what you are seeing.

[Pete M]

6 minutes ago, 89 MJ said:

Just knowing it is the floor tell me that there is more rust than what you are seeing.

 

 

just knowing it's an MJ tells me there is more rust that what you're seeing

 

 

 

 

 

awww, I made myself sad  

 

 

[89 MJ]

3 minutes ago, Pete M said:

awww, I made myself sad

Awwww, c'mon Pete, rust means you get to weld in shiny, new, strong metal!

Its all in how you look at it. 

[Dzimm]

Oh I see now, this is the bottom looking up at the carpet.  Yeah you gotta pull the carpet.  The topside is going to a million times worse.  The carpet holds the moisture against the metal, under the carpet is always worse.

[Minuit]

2 hours ago, Dzimm said:

Oh I see now, this is the bottom looking up at the carpet.  Yeah you gotta pull the carpet.  The topside is going to a million times worse.  The carpet holds the moisture against the metal, under the carpet is always worse.

 

And if you don't do an extremely thorough job of examining both the top and bottom of every layer that makes up the floor system of the Comanche, it will come back. And it will not stop until your truck turns to dust around you.

[AMC86Kid]

Ok will look on the inside of the truck when I get there, currently I’ve been looking all over under the truck and can’t find any other spots, weird how it’s just rusty in the one area 

[Pete M]

that's because floors can rot out from rain + cab leaks.  other rust areas usually require salt to rot out.

[AMC86Kid]

Ok cleaned the rest of the area off and it looks fine, no other rust 

 

 

What type of new undercoat do you guys recommend ? 

[Eagle]

16 minutes ago, AMC86Kid said:

Ok cleaned the rest of the area off and it looks fine, no other rust 

 

What type of new undercoat do you guys recommend ? 

 

None.

 

Undercoat traps moisture and promotes rust. Google up POR-15.

[JMO413]

12 minutes ago, Eagle said:

 

None.

 

Undercoat traps moisture and promotes rust. Google up POR-15.

POR-15 and then to cost with your choice of paint.

[Minuit]

I wouldn't do anything until you look at the other side. Some of that metal may look fine from the bottom but be nearly gone up top.

[AMC86Kid]

Thanks for the recommendation 

I’ve never heard of Por-15 

but it looks like good stuff