From: |
Keith Johnson [keiths55(at)bigpond.net.au] |
Sent: |
Saturday, October 01, 2005 6:39 PM |
To: |
HillmanCars@yahoogroups.com |
Subject: |
Re: [HillmanCars] Re: EasiDrive transmission |
Ken
Tip from somebody who often had the need to remove sticky stuff off expensive plastic equipment.
WD 40 or CRC 5-56 works wonders and doesn't harm most plastics or (so I am told:–) the enviroment. I think it
smells good too :–))
The other little tip is that the fibreglass rod from up the middle of some radio antennas is the most useful stuff to
make various tools out of. It works like a fingernail without damaging your recent manacure and is a very good
insulator if you want to prod things with high voltage on them.
Keith
From: |
Kenneth Nelson [citbuff(at)sbcglobal.net] |
Sent: |
Saturday, October 01, 2005 11:19 PM |
To: |
HillmanCars@yahoogroups.com |
Subject: |
Re: [HillmanCars] Re: EasiDrive transmission |
You're right Keith about the WD40 – I've never seen it affect anything except the dirt! It must be a very
weak solvent. But the paint stripper really got after this ancient baked-on goo. That plastic rod in the
center of antennas is a material called "Delrin plastic". It's made by Dupont – I just retired from 35
yrs of working for them – 27 of those here in Detroit with the auto co's. Delrin has no glass fiber in it,
so it will not scratch other materials, yet it is very hard for a plastic, an excellent low load bearing
material, and resistant to all chemicals except acid – there is NO glue for this plastic or nylons – that's
why nylon is the most extensively used plastic under the hood of a car – it won't melt until it hits about 500 degrees F!
Delrin makes an excellent scraper for sensitive materials. You can also make a lot of useful
mechanical parts from it – most windshield wiper and power window motor gears are made from Delrin or
nylon (Dupont invented nylon in 1938). If anyone on the list has a question on plastics, I'd be glad to
help them understand the myriad different materials out there, and how to repair them.
Ken
From: |
Bernie MacIntyre [minxpei(at)yahoo.ca] |
Sent: |
Monday, October 03, 2005 11:52 AM |
To: |
hillmancars@yahoogroups.com |
Subject: |
[HillmanCars] Plastics |
Ken;
I hope you don't regret letting everyone know you have expertise in the world of plastics. Like me, I expect most
people are intrigued by plastics and have their own little plastic problem to be solved. Here's mine.
I am trying to repair a large crack in a plastic steering column cover on my Hillman Minx. The plastic is flexible
shiny and slippery to the touch. It reminds me of the plastic used in food containers such as ice cream tubs.
Is there any type of solvent or cement that will "weld" the crack. I find that most cements won't adhere and will just
peel off. I would love to find something that works like the plastic model cement on plastic models.
Any ideas?
Bernie
From: |
Kenneth Nelson [citbuff(at)sbcglobal.net] |
Sent: |
Monday, October 03, 2005 1:21 PM |
To: |
HillmanCars@yahoogroups.com |
Subject: |
Re: [HillmanCars] Plastics identification & repair |
Bernie, here are some ways to first identify what plastic it is: If the part has an area which is
hidden, you can cut off a small piece – just enough to hold in a pair of needlenose pliers and light with a
cigarette lighter or some other flame. If when burning it smells like burning hair, it's nylon. If
it smells like formaldehyde, it's acetal (Delrin).
Sniffing it carefully by wafting some of the odor toward your nose won't poison you – just sniff gently,
or snuf out the flame if it continues burning, and sniff the smoke. If it smells like candle wax, it's
polyethylene. I suspect it is nylon or acetal if you say no solvent will touch it, and nothing sticks to
it. In that case, your best bet is to build a strong patch on the backside by roughing up the surface with
medium sandpaper,smearing the area on both sides of the crack with a good epoxy, and laying fiberglass
cloth across the crack and letting the resin cure. If this still pops off, try going to a GM dealer or a
NAPA auto parts store and getting some 3M superstrong bodyside molding tape, a thin foam (about 1/32 inch
thick) doublestick tape, which will stick to just about anything. Bridge the crack with this stuff, then peel
off the backside protective layer, and put fiberglass cloth over the tape, sticking it to the tape, then put
epoxy resin over that combination. Let me know what works for you, and what your plastic smells like.
Ken
From: |
Bernie MacIntyre [minxpei(at)yahoo.ca] |
Sent: |
Tuesday, October 11, 2005 10:21 AM |
To: |
HillmanCars@yahoogroups.com |
Subject: |
Re: [HillmanCars] Plastics identification & repair |
Ken;
Finally got back to my plastic repair job. I did as you suggested and clearly detected the paraffin odor and
identified it as polyethelyne. I thought I'd try my hand at some plastic welding now that I was able to identify the
plastic. I found another piece of same type plastic for a filler and heated up the 47W soldering iron. On the
back side, I melted a groove about 3/4 way through the plastic and melted in some of my filler plastic to fill up the groove.
Once both the filler and subject plastic were molten, I smoothed them together. I continued this on along the five
inch crack. I am quite pleased with the result since it seems to be stable and strong. I intend to repaint the
piece with Krylon Fusion paint. I have used this paint which is designed to adhere to plastics for my steering wheel
and am very impressed with the way it adheres. Thks for your help.
Bernie