Rivet a firewall

[Matt_50]

I've got the hood from my donor taking up space and I got to thinking I bet I could cut me out one of those firewall covers. I've got so many holes it's crazy.

How do you guys feel about covering up firewall? I think getting a smoother look would look nice.

And if it is just a cover, could I just rivet it on?

[dsraven]

there was somebody on here who autobody panel adhesive'd his on. can't remember who though. turned out pretty nice if I remember. just gotta keep the panels tight if there is anything, like a hood hinge, that bolts through. maybe even drill those holes and use the bolts, with large washers to spread the load, to keep the panel tight while the glue dries. not too much glue around that area as well so it can't become a bulge when the bolts tighten. since it would be cemented on you could use filler around the edge to blend it and make it look like a single panel.
just a thought.

[svr]

Always wondered about doing the panel on the front of the fire wall, do you worry about dirt and moisture getting between the panels and causing rust and corrosion? looks like a place for things to get trapped.

[Matt_50]

I wondered the same thing, but I guess if it sealed well, it should be good. I'm sure there are many areas with pockets.

[dsraven]

make sure to epoxy prime it all before bonding. that's about the best you could do I guess. filler sticks to epoxy like poop to a blanket so no worries there. you could also epoxy patches over the holes from the back side so moisture can't get in.

[Matt_50]

So prime back of cover and front of firewall... use epoxy or adhesive, blend with filler. Here's test fit.

[dsraven]

what I meant was use epoxy primer on both hidden sides. this seals the metal. regular autobody primer all by itself is actually porous so it will eventually start to rust behind the panel you apply. soon the adhesive will let go.
I guess you could use epoxy of some sort to bond the new panel to the old panel.
I assumed you were installing a one piece panel over the engine side of the firewall to make that area look smooth and cover existing holes. are you installing on the inside of the cab instead?

[Black_Sheep]

I used 3M panel bond, there was very little finishing required...

[mongocanfly]

that's nice black sheep!!!

[Fred n' Ethel]

Originally Posted by mongocanfly

that's nice black sheep!!!

That certainly is a fine piece of work ..... and I'm including the entire project.
Many great tips for reference in the member builds here, especially this one of Black Sheep's.
Exquisite workmanship and attention to detail, a pleasure to witness.
Quite refreshing, thanks.

[Black_Sheep]

Originally Posted by Fred n' Ethel

That certainly is a fine piece of work ..... and I'm including the entire project.
Many great tips for reference in the member builds here, especially this one of Black Sheep's.
Exquisite workmanship and attention to detail, a pleasure to witness.
Quite refreshing, thanks.

I was going to weld the pieces in until a couple guys that use panel bond regularly convinced me to go that route. No regrets, it saved a bunch of welding and grinding. No warpage either, all I had to do was blend the edges.

[MARTINSR]

Yep, without a doubt the bonding materials we have now are not the "glue" of days gone by. They are used in STRUCTURAL repairs by companies like BMW.

Amazing stuff!

Brian

[Matt_50]

Is there any particular type I should buy? And then just blend in with filler? It's not a nice flat surface and towards the center, there is a tiny gap where there's a raised edge... maybe tack it and fill in?

[Black_Sheep]

Originally Posted by Matt_50

Is there any particular type I should buy? And then just blend in with filler? It's not a nice flat surface and towards the center, there is a tiny gap where there's a raised edge... maybe tack it and fill in?

It’s hard to go wrong with 3M products, just follow the surface prep instructions for best results.

[mongocanfly]

^^^^"It’s hard to go wrong with 3M products,"^^^^
I agree..buy ALL 3M products.....but I'm biased. ...I work there...and I need some 401k money...haha

thanks Martin. ...ill look at evercoat again and also see what 3m has..
i used metalglaze based on your opinion and i agree that stuff works like butter on toast..

[dsraven]

hey mono, would you need to worry about the roof distorting in heat/cold because the 2 pieces you would be jointing together would possibly move slightly, normally being independent of each other, but with the adhesive or a small tack they would be joined at a single point. it may cause the roof to distort on a hot day and may also stress the glue or tack weld causing it to let go over time.
just a thought, dunno myself

[MARTINSR]

Now Matt, that is a big issue as leaving a seam with bonding there the filler will VERY likely "ghost line". The bonding and the filler just don't seem to like one another.

That being said, BMW has you bond roof pillars with a backing behind it. The seam is ground out and then a metal reinforced "bondo" filler is used to finish it off. We just did a 2017 BMW like this a few weeks ago at work. The tech didn't want to do it and was going to weld this but we decided it MUST be done just as BMW says to do it for liability reasons and thus it was done just as this video.

https://www.youtube.com/watch?v=YGC3dFCRgGM

The thing about the filler is that metal filler is about $50 a pint from BMW, that is the one we used as was all the bonding and rivets and all the other crap they want you to use, again, for liability reasons we did it EXACTLY as BMW says.

But the metal reinforced filler is available from other sources for a lot less.

http://www.evercoat.com/product-deta...ber/100889/us/

https://www.3m.com/3M/en_US/company-...3191703&rt=rud

The funny thing is, this stuff has been out for decades, we used it back in the 70's I used a pile of "Alumilead" by PPG back then. It later was laughed at. But apparently, like epoxy primer that was also big back then and then died off it's back.

Brian

[MARTINSR]

The brand we use at work isn't available in the retail market but are basically the same as many that are, like 3M.
https://www.3m.com/3M/en_US/company-...94857497&rt=r3

Evercoat's is interesting in that it doesn't need a special gun to use it.

http://www.evercoat.com/adhesives/us/

Personally, I am a big Evercoat fan, if they made TV's I would buy one.

Brian

[mongocanfly]

Martin. ..which one of the evercoat adhesive do you recommend? ...I've got a ongoing progect for a overhead console to hold a radio....I can partially fasten it with screws above the rearview but as it comes across the inner roof its gonna need (glued) to hold it...its a single panel roof so I can't use screws

[MARTINSR]

Originally Posted by mongocanfly

Martin. ..which one of the evercoat adhesive do you recommend? ...I've got a ongoing progect for a overhead console to hold a radio....I can partially fasten it with screws above the rearview but as it comes across the inner roof its gonna need (glued) to hold it...its a single panel roof so I can't use screws

I am not using them so I don't know, it's pretty basic though, if it says the adhesive for metal, get that one for metal. If it says for plastic, get that one for plastic.

800813 looks like the one. Notice that they don't say "structural" for liability reasons! But there are very similar products that do.

Notice that they will often be very similar and only change by the cure time. The longest cure time is not a big deal, put it together and leave it for the day, it's not like you are going to be needing to unclamp it in the next hour to go to a show.

But at the same respect, look at the heat needed, you don't want to bond it and leave it over night when it drops to 20 degrees in the garage, that is NOT good with these bonding adhesives. Always look at the heat needed and give it accordingly.

Brian

[Matt_50]

I'll post a pic in a couple days to show what I mean. I can see in the kits that they are shaped just right in that little spot.