Plastic welding

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Clip4

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I watched a video on the current welding technology for repair automobile bumper covers. Would this work in cracks in aircraft wing tips?
 
It should work, as long as it's plastic and not fiberglass. BUT... I've tried it on other things (using a rig I borrowed from work), it's not nearly as easy as the videos make it look.
 
Clip4 said:
I watched a video on the current welding technology for repair automobile bumper covers. Would this work in cracks in aircraft wing tips?
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I used fiberglass resin and a few layers of fiberglass cloth on the inside of my plastic wing tips. It has held up surprisingly well.
 
For model rocketry I have used fiberglass drywall cloth, baking soda lightly dusted on it, and saturated with cheap liquid super-glue. You can do some thick buildups that sand well. Fumes will kill ya.

I have used this for plastic panel repair along with the Bondo finishing stuff that comes in a tube to hide the joint on the front side.
 
I have a 1976 Apache Camper. It is a hard sided pop-up. A large portion of the camper is ABS plastic. The standard repair method is to melt ABS with MEK/MEK Substitute/Acetone to make a slurry. You can then repair the part with the slurry.
 
Clip4 said:
Would this work in cracks in aircraft wing tips?
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It will work provided the tips are plastic as mentioned earlier. However, I've found the repair doesn't last long. The best route is to make a permanent repair with one of the proper plastic repair methods out there.
 
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as capt thorpe said, it depends on the type of plastic. we weld poly pro all day long. its an easy process, if done right its strong, and lasts forever. but it is really depends on the type of plastic.
 
I fixed a plastic arm rest by using fiberglass weave cloth on the backside and West systems G flex resin which is a more flexible resin designed for plastic structures. Works well and provides more strength for the plastic part than original while retaining flexibility.
 
I cut shallow v-shape valley's in the plastic with a dremel, filled with the ABS/MEK slurry as @DFH65 talks about for the wheel pants.
For some of the thinner things, I taped over the front side of the crack, then just forced it into the crack, and created a build-up (or piece of ABS as a patch) on the back side if it didn't interfere with anything. Repainted if necessary. So far so good.

Also found that a prescription bottle didn't melt when using to mix the MEK. I was very skeptical lol
 
DFH65 said:
They do. I think it is the same. I always made my own.
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The only thing I see is the make an Extra Special for extreme heat and cold use.

Oatey 30918 ABS Extra Special Cement, 16 oz, Black
 
That oatey stuff is "cement". As far as I know it's like the solvent, or glue....it doesn't contain filler material

which is what the abs plastic does that is dissolved in MEK .... that is more like a filler putty

Many years back I remember reading an article about using ABS plastic in the form of legos, 'melted' in MEK an used as a filler....
in conjunction with some sort of putty to make a mold. The putty was pressed into the "leather-ette" texture of some undamaged interior panels from the aircraft. That textured putty was then used along with the 'melted' ABS plastic to mold a nice looking textured repair to match. I don't recall what the putty was...playdough, or at least something of a similar nature....
 
Clip4 said:
The only thing I see is the make an Extra Special for extreme heat and cold use.

Oatey 30918 ABS Extra Special Cement, 16 oz, Black
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“Extra Special”? Is that just ridiculous marketing hype, or an actual defined term like “extra virgin olive oil”?

I see they have a “Medium Black ABS cement”. Is there a Special Medium Black ABS Cement as well as the Extra Special version?
 
RussR said:
“Extra Special”? Is that just ridiculous marketing hype, or an actual defined term like “extra virgin olive oil”?

I see they have a “Medium Black ABS cement”. Is there a Special Medium Black ABS Cement as well as the Extra Special version?
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It is formulated for use in the hot and arid climates in the western United States according to manufacturer.
 
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Gary Ward said:
I used fiberglass resin and a few layers of fiberglass cloth on the inside of my plastic wing tips. It has held up surprisingly well.
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I used to do that until I found out that most of the interior and exterior plastic stuff is ABS. Acrylonitrile Butadiene Styrene. Same plastic used in household drain pipes. The black pipes. If you go to the building supply (Home Depot Aircraft Repair) you can get a little can of ABS solvent cement, and it's just ABS dissolved in MEK. It's yellow. You put some tape over the crack on the outside of the fairing or panel, to keep the crack aligned and to prevent any bleed-though of the cement, then clean the backside with MEK, which also primes it, and then cut some fiberglass cloth (not mat) patches to fit. Best is to cut it so the weave is 45° to the crack; this gets all the fibers working for you, and cut that way, it will conform easily to compound curves. Wet the surface with the yellow goop, press the cloth into it, adding another layer if necessary. Don't overdo it with the goop.

Fiberglass (polyester) resin only sticks to the plastic, and it often peels away. The ABS fuses itself into the plastic, and it ain't coming off unless you didn't clean the surface well.
Capt. Geoffrey Thorpe said:
Impossible to say without knowing what kind of plastic is involved.
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ABS. Never seen anything else used unless the fairings were fiberglass.
DFH65 said:
A large portion of the camper is ABS plastic. The standard repair method is to melt ABS with MEK/MEK Substitute/Acetone to make a slurry. You can then repair the part with the slurry.
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The Cessna R182 service manual actually suggests that for cracked fairings, but it really doesn't work well at all. It's difficult to get good fusion along that narrow interface in the crack. Got to use MEK; nothing else fuses well. The manual says to shave some ABS off the fairing in an obscure place and dissolve the shavings in MEK.
 
Dan, does ABS cement stick to fiberglass cloth? How about the commercial ABS/PVC/CPVC cleaner?
 
Clip4 said:
Dan, does ABS cement stick to fiberglass cloth? How about the commercial ABS/PVC/CPVC cleaner?
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ABS cement sticks real good to fiberglass cloth. And fingers. And almost everything else.

The MSDS for the Oatey ABS/PVC/CPVC cleaner has these ingredients:

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