Ever tried to cut a taillight lens?
 

Can it be done (cleanly)?

I have two broken w123 wagon tail lamps that I would like to make into one for the moment....

I once experimented, years ago, on one off a volvo using a dremel with a cutting wheel but it just melted the plastic into a mess.

This is extreme make over.
 

Never done it as I would try to pull one from a JY. I would expect it can be done with a good hack saw. Can you do a test cut, just cut away the broken part, but not the intended line and see how it looks? You probably need to sand the cut line then glue the 2 halves together. Interested to see the end result.

Good luck.

I have a variable speed Dremel and an adapter that allows to use of a HSS circular saw blade about 1 1/4" in diameter, I'd bet that such a tool could be slowed just enough to prevent it from melting the plastic but still rotate fast enough to reduce the chance of kickback that a slow turning blade does.

The saw adapter has a spring loaded guard so it's pretty easy to expose just enough blade to get the cut done without having a crasy spimming blade waiting to amputate a finger!

Agreed, the melting is caused by the tool spinning too fast or if it were a band saw, same idea but in a straight line.

i would be tempted to use a fine-toothed blade, maybe a masonry blade, on a chop or miter saw. leave enough room for the kerf to be melted and messed up and when you get the burned plastic piling up at the edge it can be wirebrushed off before gluing. paramount would be cutting a straight line, which is what i think would be hard to achieve using a dremel.

You would have a better chance of cutting a straight line with a Hack Saw using a fine tooth blade. Also you wouldn`t get the plastic hot.

I think Acitone would work to attach the two pieces together. that would depend on the type of plastic I would guess.

Charlie

I wonder if he is waiting on the free 300TD rear passenger tail light lense from me to attempt this procedure.

Melting plastic is due to high cutting speed. Cutting by hand with a fine tooth hacksaw would work, make the cut further towards the bad section allowing you to finish sand. ( A hack saw will give you a straight cut where the rotary tool won't )

The plastic is very brittle so don't put too much pressure on the cut.

If you were using the brown / black abrasive cuttings wheels, they cut by abrasion rather than cutting chips increasing heating.

those tiny saw blades work great for plastic. I use them routinely for interior trim modification, and even used them when repairing my Euro headlamps and for the HID retrofit in my Sebring. I use a generic set from Horror Fraught, and this leaves me with no safety guard, so I use only my cordless Dremel with them because it lacks the torque of the corded beast.

Also, anyone that thinks a straight line can't be cut with a Dremel just hasn't learned the trick, yet. I do it all the time, and consistently, at that. You have to keep your eye ahead of the cut, Kinda how you watch down the road as far as possible while driving. (Unless you just stare at the tail lights of the car in front of you, in which case you are probably doomed to never make a clean cut with a Dremel.)

Water jet will cut just about anything, initial cost is probably a bit high. If you go to home cheapo, you should find a coping saw set, about $10, will get you a coping saw and several coarse to fine blades. Mark your cut, take your time. Seen lots of failed attempts to bond to taillight plastic. Might scuff a spot and use JB weld or some epoxy. 5 minute epoxy will yellow, I don't know if polyester resin will.

at this point, just buy a good used one. Your time should be factored into the cost and if my time spent hacking a part together is more than buying a good used part or new is more then I just buy the new part.

Good grief... those lenses are turning into gold by this point. Upon my return to the US I may coordinate a group purchase at $50-$70 a piece brand new. If that does not drive the prices down, nothing will!

Teye-eye-eye-ime IS ON MY SIDE! Yes it is
 

I get the impression he has the time to invest. One could sink just as much time trying to hunt down a "good" used example. Unblemmed originals are AKA unicorns.

I second the fine toothed hacksaw followed with the sandpaper. Much more control over everything. It only takes one misplaced oversized tooth to catch the plastic and ruin your donor piece. Tool and piece in a fixed position to help with straight edges. Think meat slicer here. Belt sander on low speed sounds perfect. Can they be run slow enough?

MBZ123

Ever the devil's advocate =>

Has anyone tried using heat to cut these lenses before?

Something like this might work

Hot Knife thermocutters for all your plastic cutting needs

I would not want to try heat.

as for Joe (TheDon) comment, I have several broken lenses I have kept in case I needed at some point to cut them and build a new one. When I first started with the 123s twenty or so years ago, parts were pretty expensive, now they are still fairly plentiful but eventually all the cheap used parts will get used up and unless someone builds new parts the old ones will become more expensive and make the repair more worthwhile.

OTOH the OP may just enjoy the challenge of repairing a part.

When the Mrs. PT Cruiser was still pretty new we backed into another of our cars and broke the taillight lense into about 15 pieces. A new one or good used one was over $150 so I picked up the pieces and glued them all together, thinking before I sold it I'd just get a good used lense. eight years later we traded in the car sight unseen so the mended lense stayed. $100+ saved and some satisfying time spent mending something broken like Humpty Dumpty.

NAIL

HEAD

BANG

So didja ship 'er yet :D???

Says the man who has obviously not recently shopped for a used w123 wagon RIGHT lens :eek:.

I tried to buy one off a guy who was parting two w123 wagons on the parts for sale subforum. I got this like, dude, like rant, like dude, like it's cold dude and I been skiiing all day so like dude I want like $80 plus one hour labour plus postage to pull it 'cause it's cold outside dude.

Any reasonable, not-substance-altered humans on this list want to sell a decent one... drop me a line :D.

I think my 85 euro still has lenses in it.. I'll look.

Even the sedan lenses are getting pricey you ask me, but you wagon folks have really got it bad. If I can find the time, I will go try a few slicing and bonding techniques on the broken lens from my parts car, and report back. I feel that the previous suggesting of leaving a little of the bad lens section on each piece you intend to reuse and sanding it down to the final cut line with a belt or block is going to provide the best results. Wetting the bonding edges with acetone or MEK and clamping them is also likely to be the best bonding method.

Haha
 

I pictured Floyd from "True Romance" as I read that.

Yeah, saying he wants labor to pull it is a crock. WE. You might not do much better on pricing though. What's your budget? I might just have a few around here somewheres.:rolleyes:

There is a saw blade for circular saws called Ti-Cut that are specificaly made for hard plastic, no chip welding and are a thin profile so you don't loose a lot of material.

Believe it or not this will be the third I have put onto this car in two years. I paid $35-65 plus shipping for the others here and on the Bay. The car isn't a pile of beauty, hence the taillights need not be either (within reason). Also, not to whine but I am a Canuck and if you haven't shipped anything the size of a taillight cross-border in the last 24 months... be prepared for sticker shock from USPS.

I DO plan to piece one together from my current one and daw_two's broken one, but the key to success here will be to keep that one in reserve after I put an intact one on the car. I have discovered that whatever I hoard as spare parts... never fails on my cars. :D

Hence I expect the result of this cunning strategy will be that the next taillight I install will last until at least 2020.

Seriously, let me know if you have one, anyone, but I want to see DT's one when it arrives to see if it will make do.

for you just have it sent UPS and held at the depot in Plattsburgh or Dundee. Cross border and install it on the car in the parking lot...

Zach,
After reading this convoluted thread, I still am not sure if you really want to merge two broken lenses.

I have no good ones to offer, which is a pity, because then we wouldn't need to use USPS.

What I would do, is cut with a fine tooth blade - rotary on dremel or manual. But cut about 3/32" away from desired line for both parts. Then use a sanding machine and carefully sand both parts to the marked lines. Do it slowly, but even so, you may get some melting. Let it harden and cut away excess with a knife.

Once both parts are cut and trimmed, next step is to glue. But what glue? Ideally something clear. Depends on type of plastic the lenses are made from. Maybe a hobby shop has a suitable plastic glue? Weldoon has many adhesives. 3M have also have many plastic adhesives. Cyanoacrylates (crazy glue) might work. Maybe NAPA has a specific taillight glue?

Have fun!

Found five minutes to take a broken chunk of red lens to the 270 FPM belt sander. It sands pretty well. Just used a light touch. You really have to shove the piece in to the belt for it to start melting.

I'm not sure but I suspect that I could cut it straighter with a saw than cutting long and trying to sand it square. With model cement it does not have to be perfect.

Cutting the lens and gluing it back together will likely not look as good as a replacement unit.

If W123 tail lights are that rare for some people, let me know if you need any. I see lots of W123s in the yards down here but I pick very few parts from them because I have a W126 and most parts are not compatible. I can't justify buying parts for a car that I do not own but if someone wants me to pull parts for them, I can do that. Just pay PNP price plus shipping and give me a little to wet my beak and make up for my time; I'll be happy to pull small parts like that for members here. I'm at the yards at least once a month looking for parts for my car, so it's not like I won't already be there.

Wanna go super custom?
 

Another possibility you might wantto try is making the cuts at congruent angles. The result would be much less noticeable. Plastic would require you keep the angle moderate though.

Better options would be: make the cut at the color change or the bottom of one of the horizontal projections? (technical nomenclature unk.)

Snap some pics. May just find someone here suggests a technique that hadn't crossed your mind.

I'd sure be curious. The DS/LHS taillight of one pair I currently have has a chip near the top of the amber around the tailgate end. A little smaller than a dime-sized semi-circle. I contemplated attempting the same fix, cut & epoxy, but decided not to. Hardly noticeable with lift gate closed. This could change my mind.

MBZ123

use a wood cutting blade on a chop saw. you're using an abrasive cutting wheel on your dremel which is designed for cutting metal. count your fingers when you're done.

The chop saw may be the best idea yet. I'd use a fine tooth blade designed for plywood I think. With allowances for the blade thickness you should be able to get it almost perfect. The 123 sedan has a sizable straight and flat surface to work with, I cannot remember off the top if the wagon light is the same in that respect or not.

Hmm. I have never cut that kind of plastic on a chop saw, but I have cut acrylic on a table saw. Feeding slowly with a fine blade is the key to success. I highly recommend covering the cut line with masking tape to anyone that tries it with any kind of large circular blade.

Bull in a China chop!
 

I agree, using a chop saw smells like disaster. Fine for pvc, abs, etc. but not ideal for 30yr old tortured plastic with no will to live?

Smaller type cutting tools reign for this application. Put the piece in an xyz vise and rig the dremel. You got your straight cut and rate control. Done.

Good suggestion on the masking tape. You could also try aiming compressed air (pc duster/shop air) across the contact area to deal with heat.

Heck, if you have access to one, a cnc or even a waterjet might be the best solution.

Piece mentioned in post #28 is attached for reference. Good luck putting a large blade to a sexy curve like that.

MBZ123

I'm in the habit of grabbing everything of value at the salvage yard these days for when the parts are not available. Around here the stream of junk ones seems to be slowly drying up. Except VS tech. Not sure how he does it man! I'm takin the day off work to go out across the state to a 240 that just showed up on the radar. I'm squirelling quite the impressive storage room of parts...

Ive got some wagon tail lights ,$30 each if you interested>,also have the luggage rack bars $70 for 2.

... I buy entire cars when I see them...:D

I will take the passenger taillight. PM sent. Tks

The most effective way to do it w/o major damage would probably be baking it. Read this http://http://clubsciontc.com/forums/diy-install-guides-23/diy-how-to-bake-open-tail-light-fix-tyc-tail-light-46447/

I used to work at a sign shop and we made signs with acrylic, it is virtually impossible to mechanically cut acrylic with out loosing material in the process so it will probably not fit/seal correctly again after cutting. Just my $.02 Hope it helps.

Club Scion tC - Forums - DIY: How to Bake/Open Tail Light/Fix TYC Tail Light
For some reason the link above didn't work so here it is again. Google "baking a tail light" and you will get a lot of info about it.