Posted September 12, 20231 yr comment_656972 My 79 zx has a small rust buble, about 1 1/2 inches square, over/under the top windshield trim. The windshied is cracked and scheduled to be replaced. I want to repair the rust buble while the glass is out. I suppose Bondo could do the job but is there a better product that would be as easy and better to use? Edited September 12, 20231 yr by mayolives Link to comment https://www.classiczcars.com/forums/topic/68551-better-than-bondo/ Share on other sites More sharing options...
September 12, 20231 yr comment_656973 I don't know what your body work experience is but that 1.5" rust spot will probably be 3-4 x as big once the glass is out and you start digging, if you find perforations in the metal you are going to want to cut that metal out and weld in new metal. If it is just surface rust make sure you get all of it down to bare clean metal. If you can, epoxy prime the area before you start using the filler, bondo, Evercoat,UPOL they are all good products. Link to comment https://www.classiczcars.com/forums/topic/68551-better-than-bondo/#findComment-656973 Share on other sites More sharing options...
September 12, 20231 yr comment_656974 If you must use “bondo” on bare steel (don’t! Prime it first, epoxy primer is good), use the short strand fiberglass filler rather than regular light weight filler. It soaks up WAY less moisture from the air than standard bondo. Standard bondo on bare steel is the fastest way to get that steel rusty and have that bondo go byebye. Link to comment https://www.classiczcars.com/forums/topic/68551-better-than-bondo/#findComment-656974 Share on other sites More sharing options...
September 12, 20231 yr comment_656975 Bondo ( plastic body filler) is really not a suitable material for dealing with rust holes. It is not water proof so moisture can travel through it and continue the rusting process. Grannyknot is correct that the hole is probably larger than you suspect once you get back to sound metal. I also agree with the sentiment that you need to get the metal clean. I would also add a step of treating the rust with a phosphating chemical. This chemically converts what minor rust is left. If I was going to try to fill a hole after this and didn't have access to a welder then I would use short hair fiberglass resin. Fiberglass resin is totally water proof after it's cured. But bare in mind that fiberglass resin gets much harder than filler! It's harder to shape and finish well. Once the hole is sort of filled and sealed up you can use filler over the primed resin to make it smooth. Link to comment https://www.classiczcars.com/forums/topic/68551-better-than-bondo/#findComment-656975 Share on other sites More sharing options...
September 12, 20231 yr comment_656976 I highly recommend you visit the POR 15 website to educate yourself on products for your repairs. As @Patcon recommended, once you remove all of the affected metal you need to neutralize any remaining surface rust. The POR product "Metal Prep" is one of those products and it leaves a protective barrier coating that is ready for your primer or other product. Here is your starting point: https://por15.com/ Link to comment https://www.classiczcars.com/forums/topic/68551-better-than-bondo/#findComment-656976 Share on other sites More sharing options...
September 13, 20231 yr comment_656977 This forum, https://www.autobody101.com/forums/index.php?sid=f044bf1f351a02abe241234902095df9 is a great place to learn. Link to comment https://www.classiczcars.com/forums/topic/68551-better-than-bondo/#findComment-656977 Share on other sites More sharing options...
September 14, 20231 yr comment_657002 On 9/13/2023 at 2:37 AM, grannyknot said: This forum, https://www.autobody101.com/forums/index.php?sid=f044bf1f351a02abe241234902095df9 is a great place to learn. I get a FORBIDDEN Error 403 when i try to access this resource.. is it because i'm in europe? strange.. Link to comment https://www.classiczcars.com/forums/topic/68551-better-than-bondo/#findComment-657002 Share on other sites More sharing options...
September 14, 20231 yr comment_657005 Maybe, the link worked for me Link to comment https://www.classiczcars.com/forums/topic/68551-better-than-bondo/#findComment-657005 Share on other sites More sharing options...
September 14, 20231 yr comment_657008 I'm getting the same error. Probably the EU authorities "protecting" us from learning too much..... Link to comment https://www.classiczcars.com/forums/topic/68551-better-than-bondo/#findComment-657008 Share on other sites More sharing options...
September 14, 20231 yr comment_657009 Worked for me, first brexit benefit I've found! Link to comment https://www.classiczcars.com/forums/topic/68551-better-than-bondo/#findComment-657009 Share on other sites More sharing options...
September 14, 20231 yr comment_657011 Worked for me, first brexit benefit I've found!Yeah, I hear that loudly! On that note some US based muscle car fora I used to read became inaccessible post GDPR but work again! :DThe ONLY benefit! Link to comment https://www.classiczcars.com/forums/topic/68551-better-than-bondo/#findComment-657011 Share on other sites More sharing options...
September 15, 20231 yr comment_657024 The last thing i want to do is humiliate people but.. yes, the first thing i said to myself was.. they are going to regret that! All that paperwork alone (something i REALLY HATE!!) Comes back.. tonnes of work, for what? It was just a big mistake.. get back in there! TODAY!! 🙂 Back on topic, guys, thanks for testing that site! Thanks, Chas! Link to comment https://www.classiczcars.com/forums/topic/68551-better-than-bondo/#findComment-657024 Share on other sites More sharing options...
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