Question about disassembling facelift headlights...

[makenzie71]

So searching pulls up thousands of hits but the information is mixed...different dates and clues are posted about all the lights. I have a set of facelift xenon lights I'm working on from a '03 530i. I'm told these are the epoxied variety...which is fine, I have a dremel, a lot of patience, a very small investment in the lights, and a solid backup plan.

But when I went to start messing around with the assemblies I noticed that the sealant is soft and pliable. It's softer than the stuff that's holding together my Murano assemblies, or any of the "bake apart" setups I've played with. If these are epoxied together, shouldn't the sealant be hard?

[BimmerBreaker]

Just because it is an 03 does not mean they are not bakeable. Check the production date - lights made after 7/02 are not bakeable

[makenzie71]

after that production date, still the stuff holding the lenses on is soft.

[Dking078]

The silicon isn't necessarily rock hard. It still has SOME pliability.

The only difference is if you apply a substantial amount of heat to it, it will not become soft/removable. You'll melt the plastic housing before melting the sealant.

[makenzie71]

okay so it's not really an epoxy. Hmmm...I have access to some solvents that might break it up, though. Might melt the plastic...might be worth trying...

[edjack]

Silicon is a hard metal at room temp.

[Perern]

Silicon is a hard metal at room temp.

Have you touched silicone grout? It's not hard.

[BimmerBreaker]

after that production date, still the stuff holding the lenses on is soft.
You looked at the production date on the lights (not on the car) and they are after 7/02 and they have a soft pliable glue holding the lenses on?

[makenzie71]

Yeah they’re 11/02 and 2/03. The glue is soft when I probe it, not hard like an epoxy sealant. I don’t know about how pliable it actually is, just that it was an unexpected condition. Since I’m not really in a hurry I thought it best to inquire before continuing.

[crazy4trains]

Turn your oven to 150 degrees F and leave them in there for ten minutes. If you can remove the lenses then great. If not then you know you need to start cutting.

[BimmrMeUpSnotty]

Someone’s already been inside of it, that’s all.

[computiNATEor]

Someone’s already been inside of it, that’s all.

That's my first thought, too, though I would think it would be fairly obvious. The old perma-seal stuff is not easy to bypass.

[makenzie71]

I thought that was a possibility but I would think that getting past the original sealer would damage the lights in some way. They look completely unmolested.

[rdl]

...

But when I went to start messing around with the assemblies I noticed that the sealant is soft and pliable. It's softer than the stuff that's holding together my Murano assemblies, or any of the "bake apart" setups I've played with. If these are epoxied together, shouldn't the sealant be hard?

I've done both types of headlights & seen the difference first hand in the same week. The permanent seal adhesive is like RTV. The bakeable sealant is similar to the butyl adhesive used for the door vapour barriers. It's easy to distinguish between the two. Use a dental pick or jeweller's screwdriver (something thin enough to enter the gap between the body and lens flanges) to try to gouge out some sealant. If you can scoop out a blob, it's bakeable. If the sealant resists or simply tears but hangs onto the surfaces you'll have to get out your Dremel.

[makenzie71]

Settles that I suppose. I’d say the stuff described as an epoxy so I expected it to be a hard brittle glue. This is more like a silicone sealant. Dremel it is.

[makenzie71]

Incidentally, RDL, how did you get the sealed ones apart? As said I’m looking at using a dremel and reassembling with rtv. I considered a hot knife but I’ve had mixed results with them. Just looking for methods I haven’t considered.

[BimmrMeUpSnotty]

When I open up the sealed ones, by the way, the sealant they used is urethane, same stuff they use to set your windshields in., so .... when I open those up, I order new aftermarket lenses, I then use an air saw, cut the lens open, with at least a half an inch of lens left in the channel of the housing.
once that’s done, use an Exacto knife, stick it in the channel, try to give it an angle so that the tip of the blade slices the urethane on the side and under the lens material. Then do the same on the inside, the other side of the lens, same thing, give the knife an angle so that it slices through the side and what’s underneath the lens material. You should be able to start wiggling the clear lens material, but I end up cutting slats, like every inch, I then use my dremel with the small round reaming bit, try not to hit the channel as much as possible, to continue the cut for the slats, down in the channel Grab the inch long segments with a good pair of duck nose pliers, pull them out like it’s you’re most hated internet morons teeth. Once you have all the teeth pulled, use the dremel with the same reaming bit and clean out the housings channel, the cleaner, the better. Then do what you have to do, button it up with new butyl rubber in the channel

[makenzie71]

That's what I was planning on doing...hoping there was a way to avoid destroying the lenses, though. Probably too much to hope for. I may just not worry about it since I'm going to sell them.

[rdl]

Incidentally, RDL, how did you get the sealed ones apart? As said I’m looking at using a dremel and reassembling with rtv. I considered a hot knife but I’ve had mixed results with them. Just looking for methods I haven’t considered.

I used a circular saw blade about 1" in diameter to cut the lenses. I first tried my variable speed Dremel which was somewhat underpowered and would bog down unless I went very slowly. I switched to a RotoZip which cut much faster. The Dremel would have done the job but much slower. I cut the lens about 1" from the headlight body. That took some care with the saw blade to avoid cutting through the clear lens and into the black flange of the H/L body under the lens.

Once only a strip of the lens was left glued to the H/L body I used an OLFA knife with the blade extended ~3" to cut fully around the perimeter of the lens strip remaining in the body. You'll need to cut both side of the strip as deep as possible, right back to the bottom of the body's slot that the lens strip sits in. I needed the 3" extension of the blade in order to slide it to the bottom of the slot without getting blocked. It was difficult to get the largish OLFA blade into the sharpish corners at each side of the H/L. There I used an Exacto knife with a small pointed blade that could work around the small radius. I next used a dental pick with a small "L" at the end - about 1/8". I worked this "L" in behind the lens strip and ran it back and forth to rip at the adhesive behind the lens strip that the OLFA blade hadn't cut.

I then used a wide slot screwdriver at ridges on the lens and reinforced ridges on the top of the body to twist and thus pry a section of the lens strip outward. That brought the strip outward enough that I could get another slot screwdriver into the now visible gap between the lens strip and body so I could lever the strip out a little more. With the lever screwdriver holding the strip I worked the OLFA. knife in again at an angle to cut a little behind the strip. Then move along the seam & repeated. Once I'd worked out around 1/2 to 2/3 of the top portion of the strip I used the Dremel/RotoZip saw to cut out that section of the strip. I then worked using the same general method on each free end. Cutting out that section made it easier to work along with a free end to pry and pull while using the OLFA, Exacto and dental pick "ripper" on the sections that were still adhering - roughly analogou s to pulling buried hose up out of the ground. Patience while lifting the free end helps - constant force lifting for several seconds can cause smallish sections of adhesive that the knives haven't reached to tear on their own and release. I didn't time myself, but pulling out the remnant strip of lens took ~30 minutes each light.

Once the lens strip was out I removed the black mask assy - the one that carries the Celis (angel eye) rings and the lens for the turn signal. There are 5 legs holding this mask to the H/L body - 3 along the top, 2 on the bottom. These legs have an "L" on the bottom. The "L" pads have holes in them that mate to pins in the body for +ve location. You'll need to cut adhesive away again and work gently to avoid breaking these legs. But there is better access than on the lens strip, especially compared to the tight corners.

Finally I used the knives to cut the remaining adhesive away from the walls of the slot in the body. And then used a narrow slot screwdriver to gouge the residue out of the slot. If you don't clean the slot, the new lens won't seat fully into the H/L's body's slot.