Keyser Posted November 25, 2012 Share Posted November 25, 2012 (edited) I have seen several discussion on guides and also lots of "How much to re-spray my bumper" and How to repair my damaged bumper threads. With this in mind I'm gonna try and write up this little job as a guide, (if the Mods and members in general think it's not worth keeping in guides please move I won't take offence ) I do appreciate that I have the unfair advantage of having a well equipped ZedShed (garage) and hobby level spray equipment, however you could do a lot of this yourself and the prep is labour intensive so if you get it even just ready for primer your onto a winner (it's not hard as my apprentice will demonstrate if he can you can) So the first thing we need is a damaged bumper BOB? Drive over that speed bump! Thanks! He's always happy to oblige Firstly strip all the bits off - reflectors number plate, grill, canards and anything else Bob has no badges but there are guides on how to remove them. Next access the damage remove loose and cracked shards of paint and fibreglass, it's better to replace than try and stick it back down with filler of a thin coat of resin (in my experience) Bob has 3 split in his and where they end right on the edge of the bumper you need to reinforce or it will flex and just crack away. So I ground out the end of the split to make it deep enough to repair properly Next clean and sand the inside face where the reinforcing and patching will take place I used a 180 grit sanding disk attachment on an angle grinder (Lightly!!!) it can be done by hand or with a drill attachment. sand off the loose and split material behind any splits or cracks Next step is the fibreglass, Available in kits from Motor factors or eBay or as individual packs of resin and hardener and the matting. Pre cut several patches from the matting and lay near to where they will be needed Then simply mix the resin and hardener as per the instructions on the tin TOP TIPS 1. Most people use to much hardener so it goes off to quick try not too 2. Mix in small quantities it will go off before you finish otherwise so make 2 or 3 small mixes 3. Use old plastic pots (margarine yoghurt etc) and bin them when finished along with a cheap brush 4. Wear latex gloves, save hours of scrubbing Paint the resin onto the area to be repaired then lay the matting on top (you can dip the matting into the mix but it can be hard to use as it will fall apart) paint generous amounts of resin on top. the aim is to fully impregnate the matting and remove ALL air from in or under the patch. Build up in layers until you are happy. Don't worry about neatness at this point it is easier to sand back to an edge than try and line up the matting perfectly work the corners to get the matting all the way in and remove the air Again building in layers if it needs to be built up more wait for it to dry and add more - this is a bridge on the end of a split Then sand back the excess with a course grade paper, I'm using 240 grit paper on the angle grinder but it's easy to go too far with that sort of cutting power! Then go over it with something a bit less aggressive I'm onto a 320 now Then to the filler, again plenty to choose from I use an "easy sand" option. Filler is an art (that I don't have) so the same as the fibreglass mix in small portions and build it up - I'm told lots of thin layers is better than one big thick layer anyway, Then sand it down, again working through the paper grades we started at a 120 to get the rough shape and very quickly down to a 400 Apprentice shot Now sand it again - a block is useful - I'll get a picture for the next post Second coat of filler and more sanding TOP TIP Run you finger over the repair - if you can feel a bump or a dip or a little dimple - you will see it in the paint!! You can feel the imperfections better than you can see them at this point! OK looking good? - SAND IT AGAIN! AND AGAIN OK Then it should now feel smooth and be looking something like this Now another decision what are you doing? A full re-spray or a blend? This one is a full re-spray so now the whole front bumper gets the 400 treatment, work the whole area and don't miss the awkward corners, when you think you have it just right - SAND IT AGAIN FYI we are dry sanding at the moment, we will switch to wet and dry for the final sand before paint. So that gets us to here - We will finish the prep and get ready for primer this week so the next stage will follow soon. Standard Disclaimer - 1. Don't follow this guide! 2. I am untrained, unqualified and have no idea what I'm talking about. 3. If you follow this guide and damage your car in anyway refer to disclaimer line 1 P.S - Sand it again Edited December 3, 2012 by Keyser 5 Quote Link to comment Share on other sites More sharing options...
The Bounty Bar Kid Posted November 25, 2012 Share Posted November 25, 2012 Top info from the ZedShed as always! Cheers dude! Quote Link to comment Share on other sites More sharing options...
ThriftyFifty Posted November 25, 2012 Share Posted November 25, 2012 (edited) What spray gun you use Chris? p.s. I know we're not at that stage yet Edited November 25, 2012 by ThriftyFifty Quote Link to comment Share on other sites More sharing options...
Zed devil Posted November 25, 2012 Share Posted November 25, 2012 Great guide, well done 👠1 Quote Link to comment Share on other sites More sharing options...
DoogyRev Posted November 26, 2012 Share Posted November 26, 2012 Great Guide Chris Quote Link to comment Share on other sites More sharing options...
jumping350 Posted November 26, 2012 Share Posted November 26, 2012 excellent guide chris im still doing my rear bumper been blending and sanding that b**** for months!!i am doing it on my own and waiting for tips from my looooong mate!! this will hopefully speed up the process thanks eagerly awaiting the next stage ...i knew i should of just driven it down to you months ago Quote Link to comment Share on other sites More sharing options...
Kev T Posted November 26, 2012 Share Posted November 26, 2012 Great guide well done. Quote Link to comment Share on other sites More sharing options...
Ricey Posted November 26, 2012 Share Posted November 26, 2012 Excellent guide mate........also your full of @*!# with this whole 'I don't know what I'm doing business' !!! Quote Link to comment Share on other sites More sharing options...
Keyser Posted November 26, 2012 Author Share Posted November 26, 2012 You had to ask didn't you! OK to be fair I have a collection - most are in the £20 - £60 range LVLP style I have a gravity feed gun for heavy primer But in the middle is my new toy a Devilbiss FLG-5 it is the bottom end or there line but you can pay £500 for a high end gun This job will be its first run but if it is even close to the one I tried it will be a pleasure to use Love air tools Quote Link to comment Share on other sites More sharing options...
Keyser Posted November 26, 2012 Author Share Posted November 26, 2012 Excellent guide mate........also your full of @*!# with this whole 'I don't know what I'm doing business' !!! That's just the disclamer in this sue anybody for anything world we now live in you gotta cover ya backside Quote Link to comment Share on other sites More sharing options...
RobPhoboS Posted November 26, 2012 Share Posted November 26, 2012 Excellent stuff. Whilst on this subject, has anyone tried this wipe-on method as mentioned here: http://www.detailingworld.co.uk/forum/showthread.php?t=217520 ? Quote Link to comment Share on other sites More sharing options...
Flex Posted November 26, 2012 Share Posted November 26, 2012 Once again Chris is winning! Quote Link to comment Share on other sites More sharing options...
350Chris Posted November 27, 2012 Share Posted November 27, 2012 Ahh, the joys!! Best thing about bodywork is the technicolour bogeys! Quote Link to comment Share on other sites More sharing options...
Keyser Posted November 30, 2012 Author Share Posted November 30, 2012 Part 2 (The Return) So after sanding down with a block or if you're a flash/lazy git an air powered DA We can see some bits that need more filler Mix a drop of filler - this in on the knife so it's not much Mixed Then build it up Let it dry and sand again Repeat until smooth When happy with the filler, its time to prep for paint, the zigzag marks here are from using a coarse grit (P120) to rip down the fibre glass repairs - they can show through to top coat so they have to go - 240 - 320 - 400 sanding and we have no zigzags I needed to recreate a half round feature line in the bumper that had been filtered over - I simply found a screwdriver with the right sized shank wrapped the sand paper round it and working my way down the grades recreated the dip Onto stone chips The ones that show through white are exactly that chips or holes in the paint all the way down to the base coat - if you don't remove them the will show up in the top coat especially if you're using rattle cans as they don't lay the paint on very thick. The next 2 shots give you an idea of how much you need to remove to get these little beggars smoothed out due to the number of chip[s and blemishes in this bumper I'm switching to a high build primer to try and help get a smooth finish. Onto Primer I'm using a 2K High Build Primer - This stuff is not nice don't mess with it without the correct gear!! I used cellulose paint on my Zed and went through a few fly masks That is the minimum protection for spraying you can apparently get these that are 2K rated but opinions vary the best thing is one of these An air fed mask, Why, because they are the safest and you can pretend you're a character in Halo when your all suited up That and a pair of latex gloves (SMD gains interest ) and your good to go simply hook the mask up to your spare compressor which is outside collecting lovely clean air (yes I have a stupid amount of equipment) Primer prep Get everything ready Then you need some heat especially in this weather! I use this to really bring up the temp But gas heaters produce water so I never have it on when spraying and use this to keep the shed warm when spraying - 3KW electric) Next secure you piece in place so you can get to all of it Then clean it with either tack rags or I like panel degreaser Mix your paint These are great the mix for this primer is 4:1 Primer and Hardener and I'm using 10% thinner as high build is thick and I'm using a 1.6 nozzle on the gun I used 260ml Primer, 65ml Hardener and 35ml of fast thinner giving a total of 360ml of primer about enough for 2 good coats. And apply I can't really teach anyone how to spray there are plenty of vids around and information on technique but so much affects it, what paint, the gun, air pressure ambient temperature etc etc. The best way to learn is to do it I'm OK at it I can get a reasonable finish and I have a DA polisher for the rest The good news is this is primer and even if you get it quite badly wrong it doesn't matter as you're going to flat it all down again anyway a bad job to us just means more time sanding So to prove the point the first thing I did was make a mistake I walked up to the bumper swung the gun up and a drip of paint, that I have no idea where it came from landed straight on the bumper but I just carried on I'll get it with the flat back. So after 2 coats the bumper is now here Next instalment will be prep and colour coat 1 Quote Link to comment Share on other sites More sharing options...
The Bounty Bar Kid Posted November 30, 2012 Share Posted November 30, 2012 Nice work dude! Quote Link to comment Share on other sites More sharing options...
Keyser Posted December 1, 2012 Author Share Posted December 1, 2012 Part 3 - Revenge of the lacquer! So we start today with a bucket of warm soapy water - helps keep the wet and dry from clogging up I also had a photographer Buster (don't you just hate it when your being watched ) So 800 wet and dry all over the first bit was my now dry drip any tiny blemishes can be sorted with "stopper" a very fine filler Then onto paint Mixed and ready to go starting with the awkward bits Then a "mist" coat and build up the paint Finished base coat Next up the clear coat after about 20 mins Good shot of the mist you don't want to be inhaling Getting a shine The finished bumper Before after Of course just to show how badly you can balls it up and still put it right I deliberately put a couple of runs in So I'll be showing how to sort them when it's dry enough for polishing - about 48 Hours I will leave you with this That's the reflection in the newly painted bumper - not bad, not bad at all Quote Link to comment Share on other sites More sharing options...
buster Posted December 1, 2012 Share Posted December 1, 2012 awesome work today m8.cant wait for the next stage Quote Link to comment Share on other sites More sharing options...
Beb Posted December 1, 2012 Share Posted December 1, 2012 Woohooo you got an air fed mask, finally given in to the 2k... slightly safer than my "I'll hold my breath" technique Quote Link to comment Share on other sites More sharing options...
Keyser Posted December 3, 2012 Author Share Posted December 3, 2012 Last bit So after the lacquer (or clear coat) is well and truly dry (mine is rated at 48 Hours) we can polish it starting with the run I deliberately (O yer ) put in I started with a 1200 in my DA very carefully and with lots of water - be very careful the same as polishing edges and corners will rip down to primer in seconds! so stopping and checking often the aim is to remove all the "orange peel" the thicker swirls are the run slowly coming down. over to a 2000 grit and by had we want a flat dull surface all over This is not easy to photo with my cheapo camera in artificial light but you get the idea keep going until its all that dull look, Then out with some more toys rotary polisher and some aggressive compound then onto a DA and something a bit less aggressive again the same applies especially with the rotary watch the edges!! When it's finished it should be like glass - mine came out like this (best pic I could get) and the finished article hope it helps someone - good luck with it The End. Quote Link to comment Share on other sites More sharing options...
theheff Posted December 3, 2012 Share Posted December 3, 2012 awesome mate. Quote Link to comment Share on other sites More sharing options...
The Bounty Bar Kid Posted December 3, 2012 Share Posted December 3, 2012 Well done and I'm sure others will agree with me when I say on behalf of the forum, Thanx! Really useful dude! Quote Link to comment Share on other sites More sharing options...
glrnet Posted December 3, 2012 Share Posted December 3, 2012 as usual, but I do agree with Ricey Quote Link to comment Share on other sites More sharing options...
jumping350 Posted December 3, 2012 Share Posted December 3, 2012 epic :notworthy: :notworthy: seriously impressed with that and very useful for us novices...im quite a few steps behind that but at least now i know how far along i am and need to get to...maybe a sticky??? Quote Link to comment Share on other sites More sharing options...
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