Originally Posted By: RhondaHonda
How much time do you think you'll have in the repair before painting?
Actual working time on the repair is about 1 hour not including removal or setting time for the filler. I just do other work while that’s doing its thing.
Originally Posted By: Silverado12
By now, most shops should have the equipment to fix a plastic bumper cover.
Absolutely, i would have repaired both if i didn’t score and OE Honda new front (slight blem, about 1 inch of mold flashing wasn’t trimmed on the bottom, a 1 min fix) for $108 delivered. That one was worse than the rear and repairable but would have taken 2-2.5 hr to repair, its not worth it.
It did donate filler material for hot air welding, so it didn’t go to waste.
Originally Posted By: xtell
I've never heard of that filler before but I sure am interested in trying it on one of my bumpers. Just to clarify for myself: once you smooth out the dents with a heat gun and take care of any other repairs - do you (1) sand the whole area to be worked on, (2)then apply an adhesion promoter and (3)then apply the 706 - final sand them prime? I'm just trying to figure out the correct steps to follow to get the good results you did.
U-POL 706 is available only at auto body supply stores and online. Its fantastic stuff, black color, work it just like normal filler and sands super easy without clogging the paper at all. Its smooth and when mixing it if you just fold it over multiple times to mix the hardener (mix thoroughly but don’t whip it up) it dries pin hole free.
It uses standard peroxide based hardener so don’t let the little foil pack fool you into thinking its something special. Mix it just like any other filler, use a little less hardener to get a little more working time and let it set up for 30 min before sanding
Do not cheese grate this stuff, It doesn’t grate well and you don’t want those marks in the bumper plastic.
Two last points about the 706, it has a long shelf life and a can will go a long way. The little red cap on the hardener is a break off but is threaded on the other side so you can screw it back on.
Yes get all the dents smoothed out (you probably know how to do this but for those that don’t i will elaborate) by heating the area that is damaged including any tears and holes where the dent is and pushing from behind beginning at the outside of the dent and work inwards just like it was steel.
When plastic bumpers get dented many times there will a bump raised up on the outside, just heat these and push them back down with a tool of some sort, more on tools later.
You need a heat gun for this not a hair dryer, if the paint is damaged and needs painting then you can get it pretty hot but if the paint is undamaged you need to be careful.
Keep the heat gun moving heating the entire area, the OE paint can take a good bit of heat, just get it hot enough to push the dent out or in with the tool and hold its new shape. It takes a bit of practice, an old piece of scrap yard bumper cover is great for practice before going at your expensive bumper cover.
There are not real commercial tools for this work, there is not right and wrong tools, use your imagination.
If you need a rounded tool for a complex shape use a ice cream scoop, a flat area can be done with a thick metal piece of scrap cut to a manageable size, lines can be restored using a cold chisel of various widths, old screw drivers also can be used on lines and a smooth handle also works great on rounded parts.
I use old body sheet metal dolly’s and whatever else i need i find something.
Just try to get the plastic as close to the original shape as possible, don’t worry about gouges. When done sand the plastic with 36-40 grit lightly either by had or a variable speed orbital sander set on slow speed. You don’t want to rip the plastic up too bad but you need it to be rough.
Small holes can be repaired with the 706 by just roughing up the inside with 36 grit, use plastic prep spray and using a small piece of screen, cover the screen with 706 and dry then just fill it from the outside.
Okay its all sanded down rough now to finish it. use a water based prepsol (i will link to the products used, no expensive or hard to get stuff) you don’t want solvent based prepsol on plastic covers.
Wipe it dry with a lint free cloth, never use red shop rages they contain silicone.
Spray plastic prep (adhesion promoter) 2 coats and let dry for 15 min.
Mix a small amount of 706 and apply it over the area smoothly and not too thick but thick enough to sand. If the area is large like the one i am doing break the repair up into sections, work each section individually.
After the 706 is dry (about 30 min) you can sand it with 80 grit. This is important..
Sand as much as possible only on the 706 until its right then sand it into the plastic.
The plastic sand easy and will help in final shaping but you don’t want to remove too much bumper material.
You can use a orbital pad sander on large flat areas but unless your really experienced don’t use the round DA or orbital, it will take it down fast, use a block by hand. Sanding sponges are good for curves.
If you need more 706 prepsol it down, plastic prep (adhesion promoter) just like you did the first time. the life span of dried adhesion promoter is about 30 min so reapply any time you need to cover raw plastic.
Finish sand it with 220 an then 400, feather every edge as in the pictures.
Once its all smooth, prepsol it, plastic prep then a couple of thin coats of self etching primer. Spray cans work well for this work.
when the etching primer is dry about an hour no more plastic prep spray it can lift the primer.
Cover the etching primer with flexible spray primer, multiple coats will built up enough to sand any very small defects out.
When sanding the primer be very careful not to go through, if you hit the green etching primer stop and shoot more primer.
You don’t want to go through the etching primer which is sealing the plastic because then you will need to use adhesion promoter again which can damage the rest of the primer. It can turn into a fiasco. Be careful.
Once the primer is nice paint it using the method you want. You can rattle can it, i use Chroma base and clear, the modern urethane paint does not need flex additives.
I did a lot of bumpers that have been tagged after i did them and no cracking or peeling.
Materials that work well and are locally available. The 706 you will need to go online or an auto body store.
Wax and tar remover (referred to as prepsol)
http://www.walmart.com/ip/Rust-Oleum-Auto-Wax-and-Tar-Remover-1-Quart/16652313
Etching primer.
http://shop.advanceautoparts.com/p/dupli...=etching+primer
Flex primer. I buy by the gallon but the spray can is the same product.
http://shop.advanceautoparts.com/p/sem-paints-flexible-primer-surfacer-aerosol-sem39133/22985411-P
U-POL 706 Shop around for this for better price, i pay $35 at the store.
http://www.tcpglobal.com/UPO-7061.html#.VYlxw7z7vk4
I hope this helps anyone trying to do a quick repair on their bumper. If you have access to the dent or damage from behind its best to leave it on the car, its a lot easier to work with without it flopping around all over the place.
Please excuse spelling errors or bad translation.LOL
