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View Full Version : Speaking of bumper modzzz


the poi
02-11-2008, 02:18 AM
Soooo, is there a urethane "filler" that I can use like body filler? Grafting the lower half of an 850R bumper on the 960 bumper is next on the great List, but I'm not sure what is the best to fill things with. Is there a hard urethane that I can carve/sand after setting? Also, I don't see how I can attach the half with hardware of anysort, so I'm thinking the best thing to do is leave part of the the lower 960 bumper on and glue the lower half of the 850R bumper onto the lip. Is there a really good adhesive to use for this (im thinking like, PCV cement, but for urethane). Or is the mystical urethane I'm talking about to fill imperfections the same thing I'd use for attachment. To illustrate my great plan:

http://www.pbase.com/765ti/image/76074502.jpg

http://www.pbase.com/765ti/image/76074499.jpg

the poi
02-11-2008, 02:22 AM
ah-ha: http://e46fanatics.com/features/feature.php?news_id=42

that blue **** halfway down the page. I need to get that blue ****.

Pennybridge Pioneer
02-11-2008, 02:35 AM
where's coconutcolin when you really really need him?

the poi
02-11-2008, 02:46 AM
Is the 95+ bumper TPO or non-TPO? I know their is a repair TSB for these particular bumpers to fix dents with a hairdryer, so seems like that could mean an EPDM bumper (and thus, use the TPO repair goo?) Should I use the same stuff to stick the bumpers together, or should I use a specific adhesive? 3M's site is broke, so I can't find anything really specific about their Duramix craps. But this is what I did find:

TPO repair goo: http://yhst-13811118617756.stores.yahoo.net/dur4036.html

Non-TPO repair goo: http://yhst-13811118617756.stores.yahoo.net/dur4030.html

Adhesive, but perhaps it's best used on semi-rigid plastics, and no good on the soft urethane bumpers?: http://yhst-13811118617756.stores.yahoo.net/dur4247.html

ashvolvo
02-11-2008, 02:47 AM
I repaired a damaged 850R bumper and fitted it to my 850T5, so maybe some of the same ideas might apply.

I made small 0.6mm thick aluminium plates shaped to the inside of the bar where it required joining, and drilled holes through the bar to fasten the plate.

I counter-sunk the holes and then pop-riveted the plates to the inside of the bar, with the pop rivet head through the front. I made several pieces and used lots of pop rivets.

Next I roughly smoothed the joined areas (on the front surface) with a die grinder and covered the plates on the inside with fibreglass. On the front I used a flexible filler and slowly built it up and sanded it back to ensure it still had shape.

Then applied a decent primer for plastics before I sent it for painting.

It'll be a lot of work, but it'll be worthwhile.
I'd say a similar approach might be suitable to what you're doing, its just a case of cutting your two front bars to get a decent starting point.

ShadowofBob
02-11-2008, 02:53 AM
Didn't Nicky Choy do this exact same thing on his v740r? I'm sure he has info.

http://www.turbobricks.com/feature/img/summer_05a.jpg

"The air dam and rear bumper are combinations of a 960 top half mated to a V70R lower half riveted together and backed in fiberglass." According to the article from the feature car section.

the poi
02-11-2008, 02:59 AM
hmmm, my original thoguht was rivets, but I was wondering how the heck i could countersink the rivets into the 1/8" thick bumper. Ash--I guess you did that, how'd you do it?


edit:// oooooooooooo, 13 ounces! http://www.levineautoparts.com/3mauezsaflpa1.html

ashvolvo
02-11-2008, 03:21 AM
hmmm, my original thoguht was rivets, but I was wondering how the heck i could countersink the rivets into the 1/8" thick bumper. Ash--I guess you did that, how'd you do it?


edit:// oooooooooooo, 13 ounces! http://www.levineautoparts.com/3mauezsaflpa1.html

REALLY REALLY carefully! :-P
just used 1/8th pop rivets and did the countersinking really slowly. I screwed up a couple and had to fill the holes later, but there was no science to it, just patience and trying not to rush it.

the poi
02-11-2008, 03:27 AM
Actually, considering the 850 bumper has those great lock tabs on them, I'm thinking I'll do this:

Notch the 960 bumper at the seam, to allow the 850 bumper to "snap" on
Leave a 1-2in lip underneath, and glue the lower bumper on with automix universal adhesive: http://www.levineautoparts.com/3mauunadbl20.html
Any chops I needed to make are either directly filled with flexible bumper repair: http://www.levineautoparts.com/3mauezsaflpa1.html
Anything I chop all the way through (I may need to shorten the bumper lengthwise) I back with reinforcing tape: http://www.levineautoparts.com/plrereta.html

lysolvolvo
02-11-2008, 04:46 PM
mix acetone and chopped-up abs together until you have a nice pudding, apply and let dry, sand to taste. will bond old abs together with new, fill seams, etc... will be hard like abs sheets when fully dry, may take a few days depending on viscosity and thickness of application.

triton
02-11-2008, 05:17 PM
mix acetone and chopped-up abs together...
+1 this **** is awesome, takes a LONG time to set if you mix it too thin but it sets just as hard as the original plastic and fuses the bits together, cant beat it

Rust Reaper
02-11-2008, 05:41 PM
mix acetone and chopped-up abs together until you have a nice pudding, apply and let dry, sand to taste. will bond old abs together with new, fill seams, etc... will be hard like abs sheets when fully dry, may take a few days depending on viscosity and thickness of application.


Wear gloves or your wife/GF will wonder why you have "Bum hands" for the next 3 weeks. :P

lysolvolvo
02-11-2008, 05:48 PM
doesn't come off the face either...

the poi
02-17-2008, 04:28 PM
Wear gloves or your wife/GF will wonder why you have "Bum hands" for the next 3 weeks. :P

I have perpetual bum hands, so its cool.

I'm beginning to think the bumpers are actually ABS (vivaperformance sells the 850R bumpers as "unpainted ABS"). And it looks like I won't have it easy on the inlet design--the majority of the 850R bumper will graft right on very easily, but I'm gonna have to build the "inlet" portion for the IC entirely from scratch. Pictorial explanation in a bit!

jackbombay
02-17-2008, 04:36 PM
Nchoy dealt with all this a while back, as mentioned earlier.

the poi
02-17-2008, 08:08 PM
Aye, but it was grafted with fiberglas...that's awfully rigid considering the flexibility of the rest of the bumper. Also, I've been soaking tiny chips of the 850 bumper for about an hour in a cup of acetone, and its not really doing anything. What does that say about this thing being ABS? I seems like it's a lower density ABS than like, ABS pipe, but ABS nonetheless, but I can't be certain. And every filler/bonding adhesive that is for use with ABS is labeled "non-flexible" filler/adhesive, and yet, these bumpers are, well, flexible. So what the hell.

Anyway:

http://www.pbase.com/765ti/image/93100639.jpg

Getting the bumper on in the first place looks pretty easy, the IC inlet though is gonna take some doin. Assuming I can ever find out what type of filer and adhesive to use. Hmmm.

Pennybridge Pioneer
02-17-2008, 08:24 PM
you should leave it red

Matt Dupuis
02-17-2008, 08:40 PM
http://www.exposednuptials.com/uploaded_images/bottomtooth-772504.jpg

the poi
02-17-2008, 08:43 PM
Okay, I find the marking on the bumper, they're both marked <PUR>, so its polyurethane, not ABS. So the 3m "flexible" stuff should be perfect. uhhhhhhhhhhhhhh

ya

the poi
02-17-2008, 08:43 PM
http://www.exposednuptials.com/uploaded_images/bottomtooth-772504.jpg

just like an 850!:-P

gear whine
02-17-2008, 09:39 PM
http://www.pbase.com/765ti/image/93100639.jpg


you gonna make sure that the lip is level to the ground?

anyway looks like it fits like a glove, nice work!

the poi
02-17-2008, 10:44 PM
you gonna make sure that the lip is level to the ground?

anyway looks like it fits like a glove, nice work!

oh ya, its totally wedged in there all funny right now because it doesnt fit over the lower half of the 960 bumper:)

YLD244
02-17-2008, 10:44 PM
Is there a really good adhesive to use for this (im thinking like, PCV cement, but for urethane).

use sikaflex 225

DecalServiceBrett
02-17-2008, 11:14 PM
use sikaflex 225

get on msn, whore :-P

jackbombay
02-17-2008, 11:37 PM
Fiberglass is fairly flexible, I fixed my snowmobile windshield with it and can flex it around quite a bit and it has yet to peel, crack, chip, etc...

But its hard to argue with a product designed for poly, assuming you have enough surface area to bond.

Captain Bondo
02-18-2008, 01:50 AM
I have had good success welding them together. Seriously.

Soldering iron. Cut some strips of the left over bumper to use as "welding rod".

Urethane bumper scratch filler works fine to smooth it out.

I have done this a few times FWIW.

the poi
02-18-2008, 02:13 AM
I have had good success welding them together. Seriously.

Soldering iron. Cut some strips of the left over bumper to use as "welding rod".

Urethane bumper scratch filler works fine to smooth it out.

I have done this a few times FWIW.

Woo :dance: What size iron, normal sized electrical iron or a big stained glass/lead iron? Also, any idea where I might get sheets of PU thats close in composition to the bumper to make the IC air guide?

edit:// that 3m automix flexible bumper filler good stuff?

YLD244
02-18-2008, 06:59 AM
edit:// that 3m automix flexible bumper filler good stuff?

anything 3m is good stuff. 3m rocks

Captain Bondo
02-18-2008, 09:56 AM
I just used a regular one.

As a side note though, although it should work because they are both ABS, I have had some projects where I actually couldn't get it to work right- I think it was 2 different plastics.

For example when i joined the honda bumper to my stock bumper cover waaaay back, I welded it and it worked great (mechanically at least).

The cavalier bumper would not stick to a volvo bumper. But I think it was a different material.

So practice sticking some of the 960 off-cut to the 850 off-cut.

If you can't get something satisfactory, you can use fiberglass but make sure you use epoxy resin.

You can get epoxy that is a little more flexible and of course the adhesive properties of epoxy are excellent (standard polyster fiberglass resin's adhesive properties are marginal).

HTH

gear whine
02-18-2008, 12:03 PM
oh ya, its totally wedged in there all funny right now because it doesnt fit over the lower half of the 960 bumper:)

word its all good.

cant wait to see the final product!

Pennybridge Pioneer
02-18-2008, 02:20 PM
dude jb weld them together. it is your destiny.

hokman
10-11-2008, 11:21 PM
looks fab!

rom
10-12-2008, 12:40 AM
i'm pretty sure bum hands means something completely different to our english speaking friends on the other side of the pond....

heh.. bum hands.. it's the living ass penny.