Pops-A-Dent and the plastic bumper

My wife backed our '01 Odyssey into a tree stump adjacent to our driveway.
It left a very deep dimple on the portion of the plastic rear bumper that
lies beneath the tail light area, where the bumper curves up after following
the line of the lower lip of the rear door.

She then (without asking me) went to some web site and ordered a Pops-A-Dent
thingy for $20 (I think) + shipping.

They have not fulfilled the order yet (out of stock). I can still cancel
this order if I want. Does anyone here have any experience with this
product, and will it do any good on this corner area of the plastic bumper?

Thanks!

Be

 

i think thats meant for metal where the suction cup thing can get a good
grip.

 

Can't you just reach behind the bumper and push the dent out from the
inside?

 

Some malls have a "As seen on TV" store that sells the same stuff.
A local TV station product-tested this device,and found it to be only
partially effective;it would not work on some deep dents,especially with
creases.It might even lift the paint on your plastic bumper.
You can probably get behind the bumper cover and push it out and save your
money.

 

For your reference, these devices are commonly available at Pep Boys.

You could save yourself the shipping charge and also maybe go read the
labeling in person.

 

No. I got under the car and there is too much structural material in the
way, namely the tailpipe and the bumper bars (that are under the bumper
skin). If the bumper skin itself could be removed easily, that would be the
only way to do it.

Be

 

Order cancelled. Thanks for warning me off this!

Be

 

Reach under and push your hand between the skin and rebar. There ought to
be enough flex there for you to wiggle in and push the dent out.

 

If you opt to push out the dent, it may be easier to heat it up with a hair
drier before doing so. Make sure you move it around and heat it evenly (not
just the dent, but some of the surrounding area). These bumpers are usually
PMMA and PP.

http://www.quesant.com/Gallery/Polymers/bumper.htm

If you can raise the temp of the area to over the glass transition
temperature (Tg) of the PP, this will make it easier to push out the dent.

Polypro Tg is about 100°c, or 212°f.

http://en.wikipedia.org/wiki/Glass_transition

 

Interesting. They used to be polyurethane mixes.

PMMA is plain old acrylic. Your taillight lenses are acrylic.

If you buy a tub of macaroni salad from the grocery store, its lid will be
polypropylene. Those corrugated plastic promotional pole signs you see at
gas stations are also polypropylene.

I wonder why they switched materials?

 

I believe the bumpers are polyurethane.
Aftermarket bumper covers are advertised as urethane,for better flexibility
and no cracking.

 

Urethane is also cheaper than anything except vinyl. I've been out of the
industry for three years, so I don't know if things have changed since I
left. Three years ago, all the molded body parts I was involved with were
most assuredly urethane.

Urethane's natural color is light beige, darkening considerably with
exposure to oxygen.

Acrylic's natural color is clear. Polypro's natural color is translucent-
clear. A bumper skin made of a PMMA/PP blend would look VERY different from
one made with urethane.

By the way, I negelected to mention earlier that thermoformed styrene lids
are replacing injection-molded PP lids at the grocery store deli. You'd
have to buy something off-the-shelf like yogurt to find a molded PP lid.

 

I wish it were that close. But the dent, as I described, is at the point of
the bumper after it comes out of its upward curve around the bottom of the
tailgate, below the tail light. The bumper skeleton blocks my access to that
reach, and it would be about 8-10 inches up from the opening underneath if
there were no bumper bars blocking it. A very thin item (like a long
screwdriver) _might_ fit through, but the thinness of the item would then
bring on the danger of poking a hole through the skin from the inside. I
don't think in any case that I would have the correct angle of attack. I
guess I need a really bright light to be sure.

Be

 

Well, actually, some still are PUR, though the Tg is not much
different.......PP and PMMA are less expensive materials (though the
petro-chemicals are all going through the roof and some suppliers are
claiming Force Majeure.....

 

The cost depends on the grades used. Most PURs I use are in the +$4/lb
range for the Dow grades. I think the bumpers made from PUR are actually
estane grades (formerly BF Goodrich, now the Estane group, or something
similar) and are not as costly. Most PP is quite cheap. I don't use that
much PMMA, so I'm not 100% sure of pricing. Of course, I'm not in the auto
industry (medical).

The Honda bumpers, now that I think about it, are PUR, though the process
for removing the dent would be about the same.