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Apr 25, 2013 17:26:44 GMT
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Hi all, looking for help please
Just carried out some repairs to on my old car bodywork, filled, smoothed, primed and painted. Taking a lot of time getting things smoothed out it seems Iv'e wasted a long time as after spraying cellulose paint 50/50 mix on top the repair the filler has shrunk and there is a ring around the repair. Where I was expecting a light polish and "job done"it looks a mess. Any ideas what causes this and how to overcome it please.
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v8ian
Posted a lot
Posts: 3,825
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Apr 25, 2013 17:41:06 GMT
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Probably need to use a sealer primer,
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Atmo V8 Power . No slicks , No gas + No bits missing . Doing it in style. Austin A35van, very different------- but still doing it in style, going to be a funmoble
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Apr 25, 2013 17:41:09 GMT
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Yes, you'll solve it no problem now if you block it down and spray some thick primer. The more you build up the better, the filler will absorb that too so that's why you've got to build it up.
Then block it down with some 600 wet an dry until the outline of the filler is gone. If you go through the primer use some more.
Polish the panel with some G3 then blend it in with your celly, being careful not to cut the primer out else you'll create another line that you'll see beneath the paint.
You'll be able to polish it in easier that way.
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Flat it back until the outline has gone and primer the area again and flat it that back with some 800 wet & dry. If it was me, I'd just flat/scotch the rest of the panel. Paint the primered area first (it'll need axtra coverage) and then bang a fresh layer on the panel.
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1993 Mercedes-Benz 190e LE in Azzuro Blue.
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Bioshock
Posted a lot
It aint hip to be square.
Posts: 1,861
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What filler where you using out of intrest?
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Almera GTI = ugly bird who turns out to be great in the sack = Win
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Upol "big easy" offered to me by my local paint supplier when I purchased the cellulose!!! I think it is the filler. Considering covering with bar coat to see if that works. Anyone used it?
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Bioshock
Posted a lot
It aint hip to be square.
Posts: 1,861
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Hmm Can't say I've heard of it. Was it a large area? I've stuck by Plastic Padding for dent repairs and never had a problem with their stuff. I'd have thought it would be ok though, if the paint shop recommended it
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Almera GTI = ugly bird who turns out to be great in the sack = Win
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Upol Big easy, its filler that I use on wood. Ive had problems in the past with fillers, and solvents. did you flat the paint between coats of paint? if you did that could be the issue, as the filler will absorb the thinners and swell up. the thinners evaporate over time and if the primer coats have been flatted, it will appear like the filler has shrunk. when Ive been painting,I usually prime the panels and then leave for 2 or 3 weeks before flatting them back, which gives the paint time to settle. if you havn't flatted the primer coats etc, you might find that the paint will settle in a couple of months, an be ok......watching paint dry can be interesting. these days I use metalised body fillers on bodywork and find that its more stable to use. www.ebay.co.uk/itm/DINITROL-6030-BODY-FILLER-2KG-ALUMINIUM-HARDENER-STEEL-CONCRETE-/221218490749?pt=UK_Body_Shop_Supplies_Paint&hash=item3381a6497d
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Apr 30, 2013 19:19:34 GMT
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Not that I've used it, but I believe barcoat/barcote is intended just for this sort of thing. It's supposed to act as a barrier to stop the reaction. Then it's topped with etch primer, then top-coat. So I've read, but I stand to be corrected by pro painters.
First, I'd do as suggested, sand it back to remove the reacted area, and try again.
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Apr 30, 2013 21:49:28 GMT
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WOAH STOP barcoat is NOT intended for what you are about to use it for...it is a product that is used to seal problematic substrates.....ie solvent problems.
Sorry to say this but it is the prep that is at fault....filler ringing is simply casued by not feathering it out properly....you might have thought you had !!!
Right what you need to do is relativly simple rub the are down with 400 grit using a rubber block then reprime using a high build primer over the affected area then rub that down after it has fully cured....making sure that it has FULLY dried between coats....MAX of 3 coats.....with 800 grit paper.....then reacoat with top coat.
As regards to the make of filler I can gtee you there is nothing wrong with it...I use it all the time at work.
I must admit that even I would struggle with prep work with celly paints as 2 pack is a far superior product which does not have the sinkage problems that are associated with celly.It is by it's nature a harder product.
Sorry if I have offended you in any way with what I have just said BUT I do know htat I am right in what I have just said......30 yrs in the body trade
Dave
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Then I stand corrected, Dave.
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Yeah, barcoat is really only used in extreme cases - it's not solvent based, so as to not "wake up" previous layers of strange paints, but it can cause problems of it's own hence why most people rarely use it.
You need to really really bury the edges of filler under some primer - the different hardnesses of filler and the surrounding paint will always catch you out - it'll look flat but there's always a ring.
barcoat would probably solve the problem, but proper filler primer is cheaper, will do a better job and less likely to cause other issues.
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RobinJI
Posted a lot
"Driven by the irony that only being shackled to the road could ever I be free"
Posts: 2,995
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Yeah, high-build's a much better bet than barcoat. I've recently helped strip all the paint off a TVR using nothing but a chisel thanks to someone miss-using it. The stuff was just scraping off in big flakes!
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This is what's happening, I take your advice that the primer should be applied as light coats and leave it to dry for an hour or so between coats? Just wondering why primer filler shrinks when drying? .
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rodney
Posted a lot
https://www.facebook.com/RD-vehicle-transport-and-recovery-services-525622614268010/
Posts: 1,677
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because its gone on to heavy,.
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facebook: rodney dean / rd transport
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rld14
Part of things
Posts: 351
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Whoa!
How thick is the filler? It's been my experience that any time I've used filler much thicker than about, oh, 1/8" or so I run into aggravation.
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88 BMW E28 M5
62 Vauxhall Velox
60 Vauxhall Velox
60 Lincoln Premiere Coupe
60 Lincoln Continental Mark V Convertible
54 Ford Customline Fordor
32 Ford Roadster
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Not very much at all in those two pictures. Today I managed to paint the boot and rear wings and almost got away with it with just a tiny defect. However on a door it cracked open again even though it had been prpped and left for a week. Thinking it may be the thinner that is too aggressive. It's a Churchill product.
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Personally I think it is down to the filler primer being applied to thick and subsequent coats of paint having ahigher rate of thinners in it and it causes scratch opening which in fact what this is. Only 1 cure tbh and thats take is ALL OFF and either start again using the same product or buy some 2 pack filler primer and apply it with a radiator roller and block it down with 600 paper DRY and then reapply if necc than go for your top coat
Dave
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