Cracked MIC roof action

[Ducati1098]

Thanks. There are many SMC claims. It looks like that one is just another forum quote, right?

The thermoplastic seems Ford or supplier verified for MIC.

It's also not clear if the second link applies to MIC or Painted?

I don’t know where it’s from, I didn’t make the original post. Just showing that the claims have been around since production started and nothing else since then.
IMO it would be weird if it wasn’t accurate since SMC seems to be the industry standard for things like this. Even the Braptor fenders, quarter panels and hood are SMC according to Ford.

But if you’re looking for something directly from Ford, Webasto, CSP or whoever actually makes the top, I don’t think you’ll find it.

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[Rick U]

What does SMC mean?

 

[Rydfree]

What does SMC mean?

Sheet moulding compound - Wikipedia

 

[DarthLincoln]

@swamp2 The only article I have seen about the MIC top construction with official information from Webasto is this Ford Authority article which says:

Webasto is among the finalists for the 2024 Automotive News PACE Awards due to the fact that it's the first manufacturer to use composite panels with paper cores for a removable roof system, which debuted with the Ford Bronco.

Officially known as Paper Honeycomb (PHC), these pieces form the core of the roof panel and have to be milled due to the curved shape of the top, after which they're coated with a mixture of polyurethane and reinforced glass fibers. When compared to steel, PHC's composition ensures a weight savings of around 50 percent, according to Webasto.

It‘s crazy that Webasto was up for an industry award for this thing.

No info on the MOD top construction that is unofficially reported to use SMC. SMC makes sense since it is excellent for paint.

Also I stumbled on this 2022 article which has a comparison between the early failing “MIC 1.0” at launch and the improved “MIC 2.0”.

 

[swamp2]

@swamp2 The only article I have seen about the MIC top construction with official information from Webasto is this Ford Authority article which says:

So are we to conclude the full MIC top is:

• Paper honeycomb core (PHC)
• Covered with a mixture of polyurethane and reinforced glass fibers (per first link in post #36)
• Covered with colored thermoplastic polyacetal

And perhaps MOD (painted) top is:

• Paper honeycomb core
• Sheet molding compound - basically a thermoset fiberglass (chopped fiberglass)
• Filler/primer
• Paint

I think the last two bullets in the MIC section have been provided directly from Ford.

 

[DarthLincoln]

So are we to conclude the full MIC top is:

• Paper honeycomb core (PHC)
• Covered with a mixture of polyurethane and reinforced glass fibers (per first link in post #36)
• Covered with colored thermoplastic polyacetal

And perhaps MOD (painted) top is:

• Paper honeycomb core
• Sheet molding compound - basically a thermoset fiberglass (chopped fiberglass)
• Filler/primer
• Paint

I think the last two bullets in the MIC section have been provided directly from Ford.

The MOD (and painted) top description where an SMC skin is bonded to the top and bottom of the PHC makes sense. That’s not new technology. Then the SMC surfaces be primed and painted with standard processes.

The MIC top description I am more puzzled over. The quote in the article that the PHC is “coated with a mixture of polyurethane and reinforced glass fibers” to make the MIC top doesn‘t make sense for polyacetal from what I have investigated (I’m not a body structures engineer). Polyacetal is a thermoplastic that has poor adhesion and is rarely laminated or used as a structural skin. Instead it suggests a thermoset (polyurethane) resin with the glass fibers that is bonded and molded to the PHC. That thermoset resin is the outer surface.

Unlike a thermoplastic which can be reshaped/repaired with heat, a thermoset polymer cures chemically and cannot be reshaped with heat. That thermoset behavior makes sense for a hardtop exposed to the sun.


The claim that the MIC top uses polyacetal did not come from Ford AFAIK. The only source I’ve seen on this is this post that said it was “shared by employees of Ford/Webasto who have personally worked on the tops. So it’s either super accurate or super not.”

Then again, if the claims of polyacetal in the MIC tops are accurate, maybe that explains the delamination issues given its poor adhesion properties and deformation under heat. Maybe Webasto screwed up and chose the wrong material thinking they figured out how to make it work as a structural skin.

If I had a scrap piece of a MIC top I‘d put it under flame to see if it behaved like a thermoplastic or a thermoset polymer.

 

[11811]

Why is it that so few in these post about MIC tops mention their local environment and whether the garage is temperature controlled or not (attached garage). Does the temperature get down to 20 below zero at night in the garage? Or does the sun beat down on the garage during the summer where the temperature gets over 120 degrees? Would be helpful information when trying to understanding why this is happening.

 

[Booker’s Bronco]

Why is it that so few in these post about MIC tops mention their local environment and whether the garage is temperature controlled or not (attached garage). Does the temperature get down to 20 below zero at night in the garage? Or does the sun beat down on the garage during the summer where the temperature gets over 120 degrees? Would be helpful information when trying to understanding why this is happening.

Not everyone has a garage…

 

[Dral97]

I think the point is more that we're trying to nail down environmental conditions that might cause this. So mentioning local environment (if not stored in a garage or out of the garage for long periods) or garage conditions (if it is) will hopefully be helpful.

 

[vrtical]

I think the point is more that we're trying to nail down environmental conditions that might cause this. So mentioning local environment (if not stored in a garage or out of the garage for long periods) or garage conditions (if it is) will hopefully be helpful.

Although environment probably plays a factor in some of it, most of it is a flaw in design for the MIC tops, Webasto and Ford keep messing with the coating thickness, it was more apparent in the early versions because the spec wasn't thick enough and the quality that the machinery was doing wasn't always accurate so you got a big random number of crappy produced tops that "looked" fine from a QA check, but you can't QA the thickness. I think its pretty obvious going to the SMC approach was more accurate and better design, just Ford got stuck behind on production and the customer gets the shaft. I think with what Ford is doing with the 2026 line is phasing out the use of the MIC top or at least drastically reducing the production number.

 

[DALOLA]

Based on anecdotal information from this forum, I think it's safe to say:

The majority of MIC tops are not "defective"
The environment has little to do with it
There is little evidence to show the defects are anything more than cosmetic
Some people are unlucky

 

[TPadden72]

Although environment probably plays a factor in some of it, most of it is a flaw in design for the MIC tops...

Point is environment is the only factor a MIC owner has any control over. Unless it's a design flaw that can be somewhat overcome by aftermarket coating.

Tom

Watching:
https://www.bronco6g.com/forum/thre...ard-top-roof-fender-flares-yes-please.124734/

 

[crzyhawk]

The fact that Ford is still offering these MIC tops on ‘26s makes me think they deserve any blowback they get at this point.

The fact that they DO offer them makes me believe that the problem isn't as widespread or serious as we tend to believe. I trust Ford to be greedy. I don't believe they are losing money on the MIC tops due to all the replacements they have to do. So either the problem isn't as widespread as we think, or they are marking up the tops so much that they can afford to replace them on the cars who's owners actually bother to report a failure.

 

[Rydfree]

Why is it that so few in these post about MIC tops mention their local environment and whether the garage is temperature controlled or not (attached garage). Does the temperature get down to 20 below zero at night in the garage? Or does the sun beat down on the garage during the summer where the temperature gets over 120 degrees? Would be helpful information when trying to understanding why this is happening.

They are cracking on newly delivered vehicles on dealer lots so environment seems to have little to do with it.

 

[TPadden72]

They are cracking on newly delivered vehicles on dealer lots so environment seems to have little to do with it.

Who knows? They seem to be cracking multiple times for the same customers and not cracking for others; so environment might have little, some, or a lot to do with it.

Tom

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