Cracked Evaporator Housing Fix

[piscator]

Using fiberglass to fix my cracked Evaporator housing and related part.

Upgrading my air conditioning as part of my ‘refresh,’ I discovered that the upper half of my Evaporator Housing was cracked. More concerning, the plastic around the sides of the housing was deteriorating. I don’t know what causes this, but the plastic felt soft and almost granular. Along these cracks, the plastic seemed to be eroding, like a stream a landscape.

I checked Ebay and found used Evaporator housings, with and without Evaporators, at prices – $400, $600, $900… To rich for my blood and hard to tell if they were any better than what I had. So I got out my fiber-glassing stuff to see what we might do preservation-wise! (There’s going to be a lot of pix and some repetition).

The plastic on the top of the upper housing was not deteriorating, but did have a major crack. I drilled holes at the end of all the cracks to prevent them from continuing. On the Cracks that went through the housing I used ‘Crazy Glue.’







I filled the seams of the cracks with ‘JB Weld,’ over-top of the Crazy Glue. To give the JB Weld a little better ‘tooth,’ I grooved the seam with a pick. This is when I noticed the deteriorating plastic around the side of the housing. As I scratched at the seams, the soft plastic kept coming off. I scratched the soft plastic down to where I thought it was sound and applied the JB Weld.

I didn’t take enough photos of the housing before roughing it up to start fiber-glassing. So some of what you see is a little out of order.













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[piscator]

At first, I was just going to use the JB Weld and then paint it. But I didn’t like the idea of an ‘unobtanium’ part continuing to deteriorate. I even considered making a multi-part mold to make an all fiberglass box – but that would take more time than I had patience for. Instead, I repaired the cracks and fiberglassed just the outside of the box. I may coat the interior plastic with epoxy.

Around the outside of the housing I used a bi-axial cloth that is much heavier than necessary, but I have tons of it, so...











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[piscator]

I used ‘Peel-Ply’ over the wet epoxy/glass. Using a roller or spreader as a squeegee, excess epoxy seeps through the weave of the peel-ply. This helps to eliminate air pockets and ensure a better resin to glass ratio. It also provides a better finished surface.











Now we needed a top, so I decided to make a template.









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[piscator]

Adhesive fillers added to epoxy enhances bonding strength. I thought that might be helpful on the deteriorating plastic. Mixed to various thicknesses, adhesive (and other fillers) can be used in many ways. Most often, I use it on vertical or overhead surfaces; to prevent the lamination from falling or sliding off. That doesn't always work







I used a lighter (10 oz) cloth on the top of the housing and along the base. In this photo, I’ve already wetted out the cloth and put the peel-ply over-top. It’s not a perfect finish when I peel it off. If I’d been more meticulous, I could saved a bit of sanding





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[piscator]

So how we do… strength-wise?





Now we have to repair this cracked triangular part that fits into bottom of the evaporator housing, through the passenger foot-well.





On the flat side of the flange, I wetted out two layers of 10 oz cloth and flopped the whole thing over onto a piece of polyethylene. Now we need to build up the area that’s missing by adding small strips.





Once our build-up is flush with the top of the flange, we’ll add 10 oz cloth to this side for added reinforcement and apply the peel-ply.





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[piscator]

Here's our flange after the removal of the peel-ply, a whole bunch of sanding, filling, and finally a coat of my favorite rattle-can paint.









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[piscator]

Oops, forgot to load the last photo!



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[piscator]

Back to our box. I chose not to fiberglass the entire base of the housing. The plastic here was in good shape and didn’t seem to need it. (I also wanted to avoid the tedious work in all those nooks and crannies!)

However, at the last minute, I decided to add some reinforcing strips along the flat sides of the base. If it falls apart in the future, I add more glass.





After those strips are added, it’s all sanding and filling in preparation for paint.





But what color? Satin trim black? Or maybe something a little different. How ‘bout matching the exterior blue metallic?





I always like to leave the next owner guessing!

[tmadden2]

Unbelievable level of detail here. This is what this forum is all about. Great work!

[piscator]

Tmadden, Thanks! Much appreciated!

[bourgeois911]

Outstanding repair.

[Rawknees'Turbo]

Love it, and totally something I would do (build the hell out of a component, and make it look sweet, even when it is never seen ) - really nice work, Rob!