FE-FC Holden Discussion Forum

Technical Board => Modification Help => Topic started by: Ed on August 22, 2007, 11:35:42 AM



Title: welded bumper bars
Post by: Ed on August 22, 2007, 11:35:42 AM
Hi Guys,
I’m in the middle of welding up my bumper bars and wondering how perfect do these need to be if they are to be re-chromed.  I’ve Mig’ed the joins up, filed them down, welded up low spots, filed some more etc.  Just need to know how perfect they need be?  Incidentally the middle section has quite a bit of curvature, whereas the end bars are relatively flat.  This means you need to blend them together nicely to avoid obvious joins.

Cheers

Ed


Title: Re: welded bumper bars
Post by: FATBOY on August 22, 2007, 12:42:33 PM
better knock me some up as well ed
cheers fatboy


Title: Re: welded bumper bars
Post by: Glenn 'Stinky' Stankevicius on August 22, 2007, 02:28:00 PM
How good? the word perfect comes to mind, as once they are chromed the reflections will show up the slightest distortion.


Title: Re: welded bumper bars
Post by: Ed on August 23, 2007, 10:31:52 AM
How good? the word perfect comes to mind, as once they are chromed the reflections will show up the slightest distortion.

ughh.. more welding and filing to go in that case.
silver paint is looking an easier option...



Title: Re: welded bumper bars
Post by: NO NAME on August 23, 2007, 07:09:23 PM
better knock me some up as well ed
cheers fatboy
i am ahead in the que

Ed, you should have had a try on some of the cactus FC bumpers i have.
 The guys at the chrome shop said they need to be perfect, i dont know what that means.
ive seen some guys at work repair stainless rails and clean the weld up with this little belt sander thingy witch made the weld dissapear.
 you might have to take it into the chrome shop and ask what they think of the weld, do you have any pics?





Title: Re: welded bumper bars
Post by: FATBOY on August 23, 2007, 07:13:54 PM
linisher is the machine your thinking off leon.yeh ed they have to be pretty bloody good as there is only so much they can bild it up
cheers fatboy


Title: Re: welded bumper bars
Post by: NES304 on August 23, 2007, 07:51:45 PM
How good? the word perfect comes to mind, as once they are chromed the reflections will show up the slightest distortion.
The bar on the summer nats champion looks awsome..... Lotsa work there.


Title: Re: welded bumper bars
Post by: Glenn 'Stinky' Stankevicius on August 23, 2007, 10:08:33 PM
I’ve Mig’ed the joins up

You might want to talk to a chrome plater before you go any further, I can recall MIG welding under chrome can be a problem as it leaves very small pits in the welds that show through the chrome. I think TIG is the way to go.
Brazing as a filler might work, but again you'd need to check with the plater.


Title: Re: welded bumper bars
Post by: NO NAME on August 23, 2007, 10:33:44 PM
on a brighter side, its been done many times before so it cant be too impossible for someone like yourself to do.


Title: Re: welded bumper bars
Post by: Ed on August 24, 2007, 08:09:33 AM
thanks for all your input guys.

From memory MIG welding is ok provided, as you guys have said, they are linished to perfection... I've been dreaming of one of those linishers you bolt onto the belt grinder.

on another note too ive noticed my drivers side bumper end is bent, so I'm after another if there is one out there with crappy chrome.

overall this welded bumper thing is a pain in the behind, but shoud look nice once finished.

no pics yet sorry should have some on monday. 

Cheers

Ed


Title: Re: welded bumper bars
Post by: mcl1959 on August 24, 2007, 07:43:58 PM
I saw my chromer using bronze to fill up bumper imperfections - it is easy to apply, easy to linish and plates very well.

Ken


Title: Re: welded bumper bars
Post by: NO NAME on August 24, 2007, 10:00:12 PM
thats what i heard but when i asked the chrome shop they said "not really", might ring them back and re ask


Title: Re: welded bumper bars
Post by: Ed on August 28, 2007, 08:40:06 AM
Just a few progress type shots for anybody interested in welding up their bars.

In general and at best the lapped joint is wavy and the bars sit at all sorts of funny angles.  To overcome this I cut most of the lapped section away leaving only about 5mm overlap at most.  Then ground and filed until the bar sat in the correct profile etc…. very tedious.

Once in place I bolted the bar down and tacked into place.  (Don’t forget to unplug the car battery and EFI computer before welding)

I ended up welding the bar to the brackets to clean up all bolts and rubbish.. as you can see I have the end bolts to go.

A filler panel needs to be welded in over the seams and cleaned up.  At this stage it looks like I will paint them silver rather than chrome.  It boils down to effort and $$$$$.  Still… the silver looks better than old pitted, flaking chrome.

So here are some pics… the car is waiting for it’s gearbox to be re-fitted at the same time, not a pleasant task without a hoist.

I also need a rear drivers side bumper bracket and number plate surround (FE front)

(http://img.photobucket.com/albums/v128/Ed74mnd/DSCF0002-2.jpg)
(http://img.photobucket.com/albums/v128/Ed74mnd/DSCF0004-3.jpg)
(http://img.photobucket.com/albums/v128/Ed74mnd/DSCF0005-1.jpg)

Cheers

Ed




Title: Re: welded bumper bars
Post by: FATBOY on August 28, 2007, 09:40:49 PM
ed have in stock the number plate surrounds looking good will be up for the drags on friday night staying at the plumpton hotel if any one wants to come over for a drink
cheers fatboy


Title: Re: welded bumper bars
Post by: weddo on August 28, 2007, 10:01:54 PM
Hi Ed,
If I were doing it, I would use a flap disk in the angle grinder and remove all chrome from the area of your welds before you continue. The chrome will only contaminate your weld and not allow good adhesion. If you have acces to a mig or tig welder you won't need to use a filler panel and your weld will be stronger. If you have only a stick welder you can still build up with some straight bead runs and then grind back with the flap disk to achieve a finish good enough for chrome or paint. Good luck with it, it looks super.

regards
Weddo


Title: Re: welded bumper bars
Post by: Ed on August 29, 2007, 10:56:21 AM
Hey Fat,

I cant get anywhere (out of bicycle range) at the moment, still stuck without transport.  the gearbox should be ready to pick up this weekend I hope.

Weddo,
After these shots i cleaned it all up with a flap disc and continued welding.
I was using a MIG, welds are a little messy but was doing very small welds at a time to avoid heating up the bar too much.

Almost finished....

Cheers

Ed



Title: Re: welded bumper bars
Post by: GMB-58FC on August 29, 2007, 11:14:43 AM
Hey Fat,

I cant get anywhere (out of bicycle range) at the moment, still stuck without transport.  the gearbox should be ready to pick up this weekend I hope.

Weddo,
After these shots i cleaned it all up with a flap disc and continued welding.
I was using a MIG, welds are a little messy but was doing very small welds at a time to avoid heating up the bar too much.

Almost finished....

Cheers

Ed



Not sure where/how your welding the bar Ed but one trick my old man showed with me chrome bumpers is if you can put both end of the bumper in a bucket of cold water whilst you weld ;)

Look forward to seeing how they turn out for you

Cheers Ben


Title: Re: welded bumper bars
Post by: Ed on August 29, 2007, 11:19:26 AM
Hey Ben,

thanks for the tip.

The bars need to be on the car to get the alignment right.... found this out the hard / lazy way. lol

Overall a simple but fiddly job.

Cheers

Ed



Title: Re: welded bumper bars
Post by: NO NAME on August 29, 2007, 05:44:10 PM
You have to go chrome so i can see how its all done and what i will have to do.