heinzboehmer's 2002 Topaz 6MT Coupe

[bigjae46]

Is that the roll cage? Hahaha

[Casa de Mesa]

The wooden dowels are cracking me up, Heinz. Your ingenuity knows no bounds! Love it! Such a simple solution to an otherwise complex problem - I mean, how would you clamp it otherwise?!?

Can't wait to hear your impressions after you let it cure for 3 hours / 12 hours / 48 hours/ 7 days and take the car for a spin.

Are you planning on having passengers in the back? Yank those seat belts if not 😁 The retractable shoulder belts are heavier than you might expect - possibly 1.5 - 2.0 lbs each, I'd suspect.

[heinzboehmer]

Got a good chunk of work in yesterday.

Mechanically removed paint from all bonding surfaces:



Dry fitted the contraption I came up with to brace the thing in place while the adhesive cures:





Each individual piece is a wooden dowel with threaded inserts at each end. One end gets a threaded suction cup and the other gets one of those swiveling rubber furniture feet. The fact that both ends are threaded allows for fine adjustments once they're in place.

Dry fit was super important cause all of these needed to get installed in a short amount of time. I didn't want to be messing around with them, so I preadjusted everything and marked the locations of both ends.

The plastic coated stainless cable that's between the seats is there just in case one (or both) of the sunroof suction cups fail. Those have an extra bracket to allow articulation and are kinda heavy. I really didn't want them to come crashing down and damage my center console, so I added the cable as a precaution.

Next came final prep for the adhesive. I did a quick sand with 220 grit on both the chassis and CF brace (yes I wore a respirator when sanding the CF). On the chassis, I did an initial isopropyl wipe to get all the dust off, then an acetone wipe and then a final isopropyl wipe (new towels for each, of course). On the CF brace, I skipped the acetone wipe as I wasn't sure if it would mess with the resin, so it was just two consecutive isopropyl wipes.

With that done, it was time to mask around the bonding area and apply the adhesive. The pot life for the SikaForce 7888 is only 10 min, so this was probably the most stressful part of the whole install. No pictures of this cause I was rushing, but this was my process:

1. Apply adhesive to the entire surface and spread it out with a cut down paint brush. This is mostly to ensure that all exposed metal is covered for corrosion protection.
2. Apply more adhesive to everything but don't spread it out. Most of this will be squished out when the brace is put in place, but it's meant to help fill in any gaps between the brace and chassis.
3. Put all wooden dowels in place, starting with the top corners and working my way down the sides, then doing the rest.
4. Remove all masking tape from around the brace before the adhesive cures.
5. Squeeze out of the car through the tiny space between the buckets and b pillars while trying not to knock any of the dowels out of place.
6. Remove all masking tape in trunk.

I did not manage to get this done in 10 min. Took me 15, but the test pile of adhesive I left on the bench was still pretty liquid by the time I was done, so I don't think the extra 5 min will cause any problems.

Pulling off the masking tape in the trunk:



Masking tape pulled off in the interior and all dowels in:



Now just need to wait for an unspecified amount of time before the adhesive cures.

I say unspecified because the datasheet is incredibly vague about how long the cure time is. It mentions that "Full cure and final adhesion performance is achieved after 7 days", but then also says the specced lap shear strength is achieved after curing for "3 h at 105 °C". Later on it says "Adhesion as well as curing speed can be improved by heat up to max. 100 °C". To add to the confusion, the CSL roof repair procedure (same adhesive) says that "the endurance strength of the structural bond is achieved after 12 hours at 20 °C".

So 12 hours at room temperature or maybe 105C for 3 hours, but you're not allowed to heat it over 100C? Also potentially wait 7 days lol.

Anyway, I'm just going to leave it for 48 hours at room temp. I might run a heat gun over it for a bit today, but I didn't initially because I wasn't confident that I'd be able to keep the surface temp below 100C.

[heinzboehmer]

Getting close to bonding this thing in. Progress has been kinda slow, but I want to make sure prep is done correctly.

Started by making myself a cocoon of drop cloths. I knew I was going to be grinding a lot, so I just went ahead and masked everything:




Looking towards the front:



Kind of a pain to get in and out of, but I was in there for a few hours yesterday and it looks like no part of my interior got dirty (even though I ended up disgusting). Worth it. Grinding is done, but still some work to go. Next, I need to do a final pass with 220 grit and then prep the surfaces for bonding

Also, these paper drop cloths are awesome. I had only ever bought plastic ones in the past, but I definitely prefer these. They keep their shape better and are nowhere near as hot. Plus, I won't feel as bad when I go to throw them away.

[heinzboehmer]

Engine bay looks amazing

Thanks!


It's finally time to get the slon rear brace wall bulkhead thing installed.

I previously test fit it and found that it fits prety much perfectly even with the vince front cups in the car, only a small amount of material will need to be ground off.

But before doing that, I went in and removed all the remaining sound deadening and seam sealer that was still in the way:




Here's how the brace fits in now:





And some pretty terrible pictures of the fitment from behind:





It's still not 100% flush, as there's some small welds and bumps in the panels that I need to grind down, but it's pretty close. Next steps are grinding (paint, vince cups and panel imperfections), cleaning and then bonding this thing in. Think I'll be able to find time to do all that in the next couple days.