resealing heater box after core replacement

[86chevyk20]

So i am replaceing my hearter core. Should i grind off all the old goop on the fire wall and reseal with like RTV??


What about on the inside of the cab where the box goes to to the back of the firewall

 

[chengny]

You know what I use - 1/2" wide X 1/4" thick window weather stripping. The peel & stick stuff from Home Depot.

It is clean, seals well and it can be curved to the contours of the boxes. And as a bonus, should ever have to undo your work, it releases easily.

Just wipe the flanges and firewall down with a solvent, cut/shape the foam to fit, peel and stick.

Works well on the A/C ducting too.

 

[MrMarty51]

Do`nt use anything silicone for sealing them heater boxes or anything else body related.
Silicone has its place,in the engine components and damm little of it at that.
A old body man here tells Me that that silicone`ll cause rust so I never chance it,I believe Him.OH crap,I guess I mifghta stirred up another bedate,I mean debate.

 

[86chevyk20]

ill go to home depot and get some of that! Are you talking about useing that window wether striping on the under the hood side?? or under the dask side??

ANd i can take my grinder and sand smooth that old sealant that is under the hood on the firewa;ll?

 

[chengny]

Both sides of the firewall.

Yes, you can use an angle grinder to clean the old sealer off (a wire cup is probably better than an abrasive disc).

 

[89Suburban]

What is the black original stuff on the engine bay side of the firewall? Looks like that spray seal stuff. Some kind of automotive body putty or something?

 

[MrMarty51]

What is the black original stuff on the engine bay side of the firewall? Looks like that spray seal stuff. Some kind of automotive body putty or something?

Also known as "Detroit Welding Compound" and it comes on a rope form,I have a box of the stuff setting here,been here for a very long time,I do`nt even know if it is still any good,might be all dried out.LOL

 

[89Suburban]

It looks sprayed or smeared on to me?

 

[DREAMER]

Pics of your work. Not concerned about the goop/ silicone situation, just wanna see more about you replacing the box...how'd you do it. Etc

 

[86chevyk20]

i will be working on it tomr and will get more pictures! i have to epoxy some of box back together....26 year old plastic does not like to be touched

 

[MrMarty51]

Just reread,You said it was a black spray on an I wuz thinkin the old grey colored rope stuff.sorry.