Jim Yanik <jyanik@abuse.gov> wrote in
news:Xns96F4662AA8F57jyanikkuanet@129.250.170.84:

> "TeGGeR®" <tegger@tegger.c0m> wrote in
> news:Xns96F453B287513tegger@207.14.113.17:
>
>> "L Alpert" <alpertl@xxgmail.com> wrote in
>> news:j-adnfZZfousJMjeRVn-uw@comcast.com:
>>
>>> BE wrote:
>>>> Order cancelled. Thanks for warning me off this!
>>>>
>>>> Be
>>>
>>> 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.
>>
>>
>> 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.

--
TeGGeR®

The Unofficial Honda/Acura FAQ
www.tegger.com/hondafaq/

 

Jim Yanik <jyanik@abuse.gov> wrote in
news:Xns96F4662AA8F57jyanikkuanet@129.250.170.84:

> "TeGGeR®" <tegger@tegger.c0m> wrote in
> news:Xns96F453B287513tegger@207.14.113.17:
>
>> "L Alpert" <alpertl@xxgmail.com> wrote in
>> news:j-adnfZZfousJMjeRVn-uw@comcast.com:
>>
>>> BE wrote:
>>>> Order cancelled. Thanks for warning me off this!
>>>>
>>>> Be
>>>
>>> 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.
>>
>>
>> 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.

--
TeGGeR®

The Unofficial Honda/Acura FAQ
www.tegger.com/hondafaq/

 

On 10/17/05 5:59 PM, in article Xns96F2C138AD206tegger@207.14.113.17,
"TeGGeR®" <tegger@tegger.c0m> wrote:
>
> 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.
>

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

 

On 10/17/05 5:59 PM, in article Xns96F2C138AD206tegger@207.14.113.17,
"TeGGeR®" <tegger@tegger.c0m> wrote:
>
> 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.
>

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

 

TeGGeR® wrote:
> "L Alpert" <alpertl@xxgmail.com> wrote in
> news:j-adnfZZfousJMjeRVn-uw@comcast.com:
>
>> BE wrote:
>>> Order cancelled. Thanks for warning me off this!
>>>
>>> Be
>>
>> 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.
>
>
> 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?

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.....

 

TeGGeR® wrote:
> "L Alpert" <alpertl@xxgmail.com> wrote in
> news:j-adnfZZfousJMjeRVn-uw@comcast.com:
>
>> BE wrote:
>>> Order cancelled. Thanks for warning me off this!
>>>
>>> Be
>>
>> 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.
>
>
> 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?

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.....

 

TeGGeR® wrote:
> Jim Yanik <jyanik@abuse.gov> wrote in
> news:Xns96F4662AA8F57jyanikkuanet@129.250.170.84:
>
>> "TeGGeR®" <tegger@tegger.c0m> wrote in
>> news:Xns96F453B287513tegger@207.14.113.17:
>>
>>> "L Alpert" <alpertl@xxgmail.com> wrote in
>>> news:j-adnfZZfousJMjeRVn-uw@comcast.com:
>>>
>>>> BE wrote:
>>>>> Order cancelled. Thanks for warning me off this!
>>>>>
>>>>> Be
>>>>
>>>> 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.
>>>
>>>
>>> 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.

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.

>
> 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.

 

TeGGeR® wrote:
> Jim Yanik <jyanik@abuse.gov> wrote in
> news:Xns96F4662AA8F57jyanikkuanet@129.250.170.84:
>
>> "TeGGeR®" <tegger@tegger.c0m> wrote in
>> news:Xns96F453B287513tegger@207.14.113.17:
>>
>>> "L Alpert" <alpertl@xxgmail.com> wrote in
>>> news:j-adnfZZfousJMjeRVn-uw@comcast.com:
>>>
>>>> BE wrote:
>>>>> Order cancelled. Thanks for warning me off this!
>>>>>
>>>>> Be
>>>>
>>>> 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.
>>>
>>>
>>> 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.

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.

>
> 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.