heinzboehmer's 2002 Topaz 6MT Coupe

[Bry5on]

That’s weird… m3 strut brace fit under my M3 wagon hood without any cutting/trimming 🤔

Mine cleared statically but contacted (just barely) dynamically. Good times!

[heinzboehmer]

Bonding time!

Started by clearing everything I could out of my way. This essentially amounted to airbox, blower motor, blower motor housing, engine beauty cover, wiper linkage (just moved that out of the way) and windshield cowl. I also covered up any openings that metal shavings could fall into:



Removing the blower motor absolutely sucked. It's like there was no effort dedicated to serviceability of that assembly when it was being designed. I did do it all with the windshield mount roughly in place, just to make sure that it was still doable. Fortunately, it didn't get in the way at all.

Gonna do my future self a favor and document the best way I found to remove the blower motor:

1. Remove the front cover. One screw up top and two clips at the bottom. I still don't know how BMW expects you to get that piece past the firewall, but with enough swearing and bending, it'll come out.



2. Remove the passenger side cover. Undo the three screws holding it in (circled) and remove the two linkages attached to it. Take note of how the linkage for the secondary flap is clocked so that it goes back together in the same way.



3. Unhook the blower motor (no need to undo the four screws of the mount) and wiggle it out through the passenger side. Be careful to not catch the vanes on the front cover clips and damage them. Also, the engine harness has to be moved out of the way for it to clear.



Anyway, back to prep.

Started by test fitting the aluminum piece for the final time and then tracing its outline on the chassis:



Then, time to sand. Started manually, but very quickly gave up. Dremel made fairly quick work of it:



I followed that up by sanding with 220 grit, then a bunch of acetone wipes to get rid of all debris and finally an IPA wipe. Adhesive next.

And then this happened:



Bad picture, but one side of the adhesive cartridge blew out the back and leaked everything that was in there.

Admittedly, this was entirely my fault. Turns out the applicator I have does not fit the 07333 cartridge. I didn't realize this until today, so I decided to fix the issue with some zip ties. It worked great until it caused one of the cartridge pistons to spin inside the cylinder and cause the mess above.

Lesson learned. Next time I need to jerry rig an applicator, I'll throw some sockets into the cartridge cylinders to spread the load.

Replacement adhesive (and appropriate applicator) ordered. Will give this another shot in a few days....

[bigjae46]

Oooohhhh! Now I understand how it fits. I've looked at the part and never understood how it would mount. lol

Maybe I missed it...any reason you chose 07333 vs 08115 (panel bond)?

[heinzboehmer]

Maybe I missed it...any reason you chose 07333 vs 08115 (panel bond)?

Based on 3Ms own recommendation

07333 is for structural stuff, 08115 is for non structural body panels:

3M Panel Bonding Adhesive Designed to meet specific strength requirements for outer
sheet metal panel replacement; panel bonding adhesive is
typically used in conjunction with welding, rivets or hem
flange joints. Panel bonding adhesives do not offer the same
level of impact resistance as impact resistant structural
adhesives and should not be used for structural repairs unless
recommended by the specific automotive manufacturer.

3M Impact Resistant Structural Adhesive
Designed to meet specific strength requirements for parts
such as frame rails, strut towers, sills, pillars and other
members where impact resistance is important. This type of
adhesive possesses a much greater ability than traditional
bonding adhesives to absorb and manage energy under a
variety of forces, especially peel and cleavage stresses in
extreme temperature conditions. Typically
impact resistant structural adhesive is used in conjunction
with rivets, spot welds or mechanical fasteners.

Document where that quote came from is attached.

[smee123]

Surface prep is king with 3m structural adhesive just like the importance on the loctite and their activators. Maybe trivial on an oil pan drain time sert l, but on anything that experiences any pulling loads or any inherent vibrations, I cant stress it enough!!