polyurethane bumper repair

[808_s13]

Ive searched the forum, and nothing came up for this. Im interested in
buying this front bumper (JDM kouki) but it has a split down the lip. You can see it
on the pic. This bumper is made up of polyurethane. Ive never worked with this type of material before. I was wondering if this is repairable. If so, what procedures will i do, what materials i will need etc etc. Thank you for looking, your help is appreciated
:wiggle:

http://images.craigslist.org/01150001020901040220080908f95297175059a1bee600c376 .jpg

-makua[ace]

[C. Anderson]

Try this. Urethane Supply Co. Mini-Weld Model 6 Airless Plastic Welder, Model# 5600HT | Spot Welders | Northern Tool + Equipment (http://www.northerntool.com/webapp/wcs/stores/servlet/product_6970_384313_384313) I have no experience using one but I know people that have used them.

[808_s13]

that plastic welder is $200.
kinda dont wanna spend that much to
repair a jdm bumper, cause the bumper is a steal.
would using fiberglass work?

ohh and thanks for the link! might consider it
if all else fails

-makua[ace]

[racepar1]

Are there no bodyshops in hawaii or something? Any good bodyshop could fix that. There are kits available for repairing urethane, I don't think a plastic welder is what you want to use.

EDIT: Here ya go, took 30 seconds with google. Searching is your friend. http://www.evercoat.com/productCategory.aspx?cat=6

[HyperTek]

good question, fiberglass is easy to repair, just messy and takes time for sanding. polyurethane obiously different.

[silpena]

you can find plastic exposy kits at body stores or u can go with the plastic welder. You can get a cheap one ay harbor frieght for like 30.00 plus some sticks. its good for in the future for interior plastics and such stuff. I wouldnt use fiberglass. Stuff is too hard to work with. Your plastic will be ruined just trying to sand the fiber glass down. The everycoat 2 part epoxy is good stuff just pretty pricey... almost the same price of a cheap plastic welder. Plastic welding is pretty easy. Its just like soldering. If u go with a fiber glass then i would recommend a light wieght short strand fiber glass filler like evercoats fiber tech or usc's proglass body. It has great strucutre, easy to work, easy to sand and pretty fair on the price. Ive used the fiber tech and its great. I might do a write up on plastic welding or bumper repairs in the future. Been to lazy to do it maybe i should next week... hmmmm

[808_s13]

I might do a write up on plastic welding or bumper repairs in the future. Been to lazy to do it maybe i should next week... hmmmm

that would be awsome. but for now, i may consider racepar1's idea of using polyurethane adhesive for the repair. ive never tried it before, but
im willing to try it. if all else fails, i can take it to a body shop. and ohh yeah, im in so cal right now. Only in hawaii from nov-jan :keke:

-makua[ace]

[tckracker]

If you're looking for a inexpensive fix, use JB Weld. I've done it in the past and it works great. I know some people will hate because there are 10,000 other ways of repairing a bumper and everyone has their preferred way but I only pass on info if, and ONLY if I PERSONALLY have tried it and had success.
1. Drill small holes on either side of the crack
2. Mix the 2-part JB Weld thoroughly and apply to the inside of the crack.
3. Put zip ties through the holes and pull the two parts together leaving the zipties until the JB dries.
4. Apply additional JB to the inside (generously because it won't be seen) and to the outside over the crack.
5. Wait 1 day for complete curing of the JB before removing the Zipties
6. Remove zipties and fill small holes and imperfections with JB
7. Again wait 1 day and sand and paint

It works great, it sounds kind of "shade tree", "Hokey", "Ghetto", etc. but it works and works well. Hope everything works out.
-Shaun

[DreamN]

^ I've done that a couple times. It does work really well especially for small cracks.

[FRoSt415]

i have done lots of body work and i think the welder is a plus but not needed. what i would do is go without the welder and drill holes at the begining of the crack and end. since it cracked all the way thru just drill one hole. get some sand paper some 80,180,220,400,800. platic epoxy glue, platic putty glaze(this is bondo but for platics), and a small fiber glass patch enuogh to cover the crack from the front and another peice to but in the back. Ok once you have drilled the hole at the very end of the crack start sanding with the 220 to remove the paint and make a nice peice for the fiberglass and epoxy to cling onto. then clean it really well then apply epoxy inside the cracked area and have something to hold it tight and together for however long the cureing process takes. then sand down/remove the resido left over and appy the sheet of fiberglass to the front or back with applyed hardner.i would suggest the back first since it is messy and ur first time might be a little messy.Then sand this down(front only) with ur 80 so its smooth but dont go thru the fiberglass doesnt need to be perfect since you are going to add the glaze on top of it. no one sees the back but if u might sell the bumper later down the road it makes it easy to sell if the patch is not visable. Now clean again and apply you platic putty with harder added and propperly mixed on top of the crack and the area that was sanded. Sand this downfirst with 180 then work with the higher grit paper as you get closer to your desired level and add more putty till you get a nice smooth and straight repair or howevr long it takes you to get tired of sanding and give up. NOW its fixed GJ but you still need to paint it so sand it down with that 400 u have and add primer. First just spray a nice light coat and then add more after 5-10 mins. Almost there so you get really excited and think your the boss but no more sanding get taht 800 and wet sand that so it blends into the rest of the bumper, kinda hard to explain but what you can do is use your hand and feel it throughout this proccess and once your finger nails stop feeling the scratches ur done sanding.Finally you need a beer so u grab one and clean the bumper with a clean rag and let it dry. So now get your base color(paint) that your bumper is and spray away and try to blend it in by spraying passed the repair area. let this first coat sit for 15 mins or how long the curing process takes between coats. Let this dry for 20-30 mins then come back and spray your clear coat over it and YOUR DONE!!! whala like new!!! dont forget to read what your paint says and take your time dont rush it should take you 2-5 days do it in stages but paint should be all one day to prevent any contamination. GL and just google painting and panel repair and find some videos on it to help u through it or PM me.

[808_s13]

^^^ thanks for the very descriptive procedures. you even included how to drink a bear in the procedure haha. im really considering doing this technique but using jb weld instead of that plastic epoxy glue. or maybe just use both.

-makua[ace]

[Zhanshi]

Ive used plastic repair glue (comes in a super glue like tube) and fiberglass to fix my bumper. Body shops usually charge an arm and leg to fix a bumper here :\ In any case, my friend's dad owns a body shop and uses an epoxy material to glue the pieces back together then fills/finishes it with fiberglass. I use Solarez to do my fiberglass work. It's UV cured and already has chopped up fiberglass strands.

[FRoSt415]

^^^^^ i forgot to say get a sanding block maybe a foam one if its really curved if not just get a firm one. i like useing these but these are mainly for wet sanding but should be good enough since your doing a small area u wont mess up the block much or if at all. http://flashoffroad.com/features/paint_truck/Scratch_remove/image/DSC01065.jpg

[Ragnarok043]

i dont think a plastic welder would work too well on polyurethane since its a thermal set plastic you cant melt them back together.

best bet would be to use fiberglass with polyurethane resin, not epoxy or polyester resin.

[silpena]

no you can weld polu urathane with a plastic welder. You just have to make sure you get the right plastic rods. When u weld ur not suppose to try to melt the bumper plastic you try to let the plastic smuther itself onto the plastic becuase like u said it will melt the thermo plastic. Oh and on the sanding blocks just get a block that fits the area that your working on and dont get a block that is soft and flexible. YOull be sanding forever on fiberglass or whatever ur using. Get a hard block a little flex is ok. You need the hard surface to put pressure when sanding.

[808_s13]

i take it that polyurethane resin is sold at places
like kragen, autozone, pepboys etc etc?

-makua[ace]

[silpena]

try napa, hust bros, or body shop supplie stores. Usally kreagan, autozone doesnt carry good stuff. Also try home depot and lowes they should carry it. YOu really cant buy poly-urathane resisn. Its in the bumper when its made but u can buy an expoxy resin or urathane epoxy resin.

heres some vids on how to do it. Hell even i learned something from this lol(the sandwhiching with spreaders).
http://www.evercoat.com/training.aspx
lots of info on using body filler, using exposys and bumper repair. Theres even a vid on door skin removal. I'm sure u wont buy their products since a tube of the epoxy is almost like 20.00 but i'm sure u can find something that suits ur budget.

[808_s13]

^^^holy shit, that was very helpful.
might look around for this stuff

-makua[ace]

[Ragnarok043]

polyurethane resin is harder to find, but you may be able to find them at art supply stores. the 2 most popular brands are "Smooth On" and "Alumilite".

[808_s13]

well, i called a bunch of auto supplies
stores and none of them carry any of the
evercoat products. i'll probably have to order
online. gayy

-makua[ace]

[silpena]

auto supplies stores wont carry ever coat products. They're premium professional products. you have to look for autobody/paint supplie stores. There has to be one around you. Theres 2 around me and i live in a small ass city lol.