HELP please

[JC]

what is the best way to repair a bumper, links to products be great & info. Not sure what the bumper is made from, pics of the damage:

 

http://i752.photobucket.com/albums/xx170/magnexed/Ebay%20items/DSC07903.jpg

 

http://i752.photobucket.com/albums/xx170/magnexed/Ebay%20items/DSC07904.jpg

 

no prizes for guessing what it is!

 

[bongo]

i want an evotech

 

it doesnt look like its cracked so you just need some filler john basically.

[JC]

i want an evotech

 

it doesnt look like its cracked so you just need some filler john basically.

 

sadly it has cracked, not too badly...

 

what sort of filler.... I was thinking of having a go before I take it to a body shop, if i decide to keep it......

 

I didn't actually mean to aquire one

[bongo]

if its cracked you;ll need to fibreglass it.

 

you'll need...

 

a couple of sheets of fibreglass or mesh

fibreglass resin

plastic bumper filler

 

you need to clean and clear all crap from behind the break and rough it up (give the fibreglass something to bond to)

apply the mesh or fibreglass

build up fibreglass

then leave to set.

 

on the front then..

 

sand down are removing all loose material

then build up patch in layers with filler wait till it sets then sand to a nice even finish.

 

not hard john,and all you surplus you can get from halfrauds.

[etrebus]

i want an evotech

 

it doesnt look like its cracked so you just need some filler john basically.

 

sadly it has cracked, not too badly...

 

what sort of filler.... I was thinking of having a go before I take it to a body shop, if i decide to keep it......

 

I didn't actually mean to aquire one

grind out cracks and drill holes at the ends to stop them spreading then i would use some fibreglass filler like p40 behind damage to give it some strength then body filler on top to smooth it out

[sortedgti2.0]

Isnt P40 a grade of rubbing paper?

[etrebus]

Isnt P40 a grade of rubbing paper?

no lol isopon like p38 but fibreglas

[sortedgti2.0]

i stand corrected lol

I used to use P40, P80, and 120 when i worked in the bodyshop years ago (about 11 years).

[etrebus]

i stand corrected lol

I used to use P40, P80, and 120 when i worked in the bodyshop years ago (about 11 years).

yes me too its also known as fibrofil lmao

[shawdreamer]

i want an evotech

 

it doesnt look like its cracked so you just need some filler john basically.

 

 

just filler?

 

and you'd expect that to last beyond the first speed hump he go's over I suppose???

 

What you have there Jc is low speed compression damage, The spider webbing gives it away as high speed damage on most all plastics either results in shattering or distinct cracking.

 

firstly Ill warn you, out of every type of damage to a bumper Ive ever dealt with, your type is by far the biggest pain in the ricter as it has a very very strong habit of returning quickly if the repair method used isnt careful and correct.

 

My method (tried,tested and proven to work)

 

1. remove any and all loose material remaining, including any of the gel coat that has pulled away from the main bumper (some people assume such light cracks as are visable in the gel coat layer wouldnt effect the main bumper material....their wrong)

 

2. Clean off the rear of the bumper behin the damage also, this area will be taking a resin coat so needs to be as clean as possible.

 

3. using a hair dryer/ heat gun, warm the entire area of damage until it is just this side of to hot to touch (this will force the main bumper material to expand and naturally re-adopt its molded shape, albiet often undiscernable to the human eye)

 

4. once the required heat has been acheived both front and back quickly apply a generous coat of Fibreglass resin to the rear (extend the coat a good 2" beyond the rear of the damaged area)

 

5. apply a single sheet of fibreglass sheet to the area while the resin is still tacky and add another resin coat, allow to dry completely

 

a good 12hrs is advisable to allow the the resin to set entirely as the heat from the bumper can often make the curing time irregular, Essentially you have now stabilized the base material of the bumper itself and can now deal with the cosmetics.

 

6. Dont bother with crack end hole drilling its pointless and will just add uneccassary work in spiderweb type damage, aslong as the bumpers primary material has remaned intact or returned to a "as good as new" state of rigidity (which it has if you followed 1-5) and the cracks have not travelled through both the gel coat and the main material, "drilling" is not required

 

7. using a rounded grinding dremel (couple of quid from any diy store) follow the lines of each of the spider cracks and increase them to a small ravine like shape along their entire length in the gel coat, the bottom of te ravine should be where the dremel contacts the main bumper material

 

at this point you should have a string of ravines extending out were the cracks used to be (you maybe tempted to simply sand the whole area right back but that would be a mistake also as I will explain further on)

 

8. again double check that no more of the gel coat has pulled away from the main bumper as this will be your last chance.

 

9. If the centre of the damage shows a piece of the main bumper material larger than a 50p piece make sure to take some harsh sandpaper to it or alternatively scour it with a brill pad or wire wool

 

10. The dremel will have likely left smooth edges to the "ravines" so carefully rub these also with some lighter grade sand paper (dont go to mad as gel coat isnt as hard as it first appears and once beneath the surface gloss its quite easy to roughen up)

 

11. with this key to all the repair surfaces you are now ready to begin the cosmetic repair process, you will need a basic plastic based filling/finishing coumpound for this...... DO NOT USE STANDARD BODY REPAIR FILLER!!!!!, fibreglass based fillers are also not advisable.

 

12. give the front area another heating but only so its warmed and not to the degree as you did the back (this will force the gel coat to undergo any expansion it might see on a day to day basis.

 

13. while still warm apply your compound to the ravines and force it down as much as possible so you end up with the ravines concaved (do not attempt to fill the damage in one go as this will cause the lower levels of compound to cure in a fashion that will not maximize its finished form flexibility) allow to fully cure.

 

14. Add a second layer to as to fill the the ravines and areas level with the original gel coat surface but not above, allow to cure.

 

15. the final layer can be minimilistic (allmost a smear) to bring the filled area above the gel coat surface, allow to cure.

 

16. sand back till flat and if desired a thin finished layer of standard body filler can be added to ease the task of final flatting.

 

all that remains then is, pre-paint wipe down, primer, colour coat...... job done and cracks wont re-appear a month later

[JC]

Cheers Lee

 

thats the detail i was looking for, the damage was caused by slowly going up the driver lol!

[etrebus]

Cheers Lee

 

thats the detail i was looking for, the damage was caused by slowly going up the driver lol!

i bow to your superior know ledge i thought it was a fibreglass bumper lol

[shawdreamer]

Cheers Lee

 

thats the detail i was looking for, the damage was caused by slowly going up the driver lol!

i bow to your superior know ledge i thought it was a fibreglass bumper lol

 

 

it rarely matters what the base material is, they ultimatly allways have a gel coat finish.