So I worked on my chop all winter last year and through this past winter i noticed a crack in my roof, the crack be came a 15" x 13" piece of bondo that came off the car , now the season is around the corner and i need to fix it , I need to know If i should start add ing body filler or somethin else to bond to the existing body filler to blend it in , so is there any exprianced body men with the knowledge to help,
You most likely have an unstable area there that vibrates too much and caused the bondo to work loose. Pics would help.
if its cracked, be it from flex or poor application or wrong material for the job, it needs to be ground out and removed. If its on a big flat spot, maybe it needs bracing behind it, if you sanded the panel with 320 and put 1/4" of filler over it, there was no tooth for the filler to grip to. For filler application it should be 36 grit to 80 at the highest. Duragl*** for 1/4" thick spots, ploy filler for thin 1/8" coats.... all done seperately.
Some pictures would help, of the area and the piece that came out. How thick is the piece that came out?
is the filler over a weld that may have cracked? you need to get all the filler off. over welds i use fibregl*** filler first,it reduces the chance of cracking and the chance of moisture reaching the body filler, then i use normal filler on top (rage gold) as you probably know metal has to be competely rust free, either by sandblasting or treating with a deoxidiser and you need tooth for the filler to bight and you should only apply body filler to epoxy primer or bare metal. also too much hardener can make the body filler less flexible and more likely to crack. and also if you have a stretched floppy spot in the metal and you try to flatten it using body filler instead of shrinking it, it might flop and crack the filler.
Maybe this is a dumb question, but why would you have an area bigger than one square foot with bondo on it thick enough to crack and fall off, on any car, for any reason?
If you didn't get it right then, why do you think you can do it right now? Seriously...take some autobody courses, or learn from someone who knows what he's doing, it's obvious you need to learn more before continuing on your course....nothing personal....you just need more training/experience! Causes for this can be many...poor welding, not filling the entire weld seam, not enough hammer and dolly work. poor surface prep, poor bondo application, bad temperature conditions, improper bondo/hardener mixing, working it too soon......and on and on.
Hey, Try this, with a 24 or 36 grit open coat grinding disc, grind back the area around and in the crack. Grind until you have nothing but good filler all around the area in question. Mix up some new filler, it may take several coats to build up to the level you've ground out. Now sand the filler to blend with the surrounding area and prime as necessary. Plastic filler should never be used in the 1/4''-3/8''thickness, especially in a door jam or hood panel, to do so would just about invite a crack. Whenever filler cracks, it usually does so for a very bad reason! S****ey Devils C.C. " Spending A Nation Into Generational Debt Is Not An Act Of Comp***ion !''
I seen them use some new filler on muscle car. Its made from some kind of liquid metal or something. Its silver like aluminum and still sandable.
Nothing new here, either....I remember when they used to package that stuff as an aluminum powder, and a liquid resin that you mixed together, over 25 years ago! Nothing is going to make doing this type of work easier, or last longer, just by using some special materials. Yes, materials have improved, getting lighter weight, easier to sand, less pinholing, but it still comes down to the foundations...good welding, good surface prep (no rust, old paint, moisture, or other contamination), giving the surface a bit of roughness for the filler to have a bit more mechanical adhesion. Working the metal to the best you can, so filler is less than 1/4" (less than 1/8" is better). These special fillers might have applications that they work well for, but if you do your foundation right, even the cheaper brands work well, and last a LONG time! And...a common misconception I hate to hear people claiming...that these fillers that claim to be waterproof will make up for lack of a fully welded seam, or leaving holes in panels to be filled. So what if the filler is waterproof? If there are holes or seams open on the panel, water still enters from the backside, creeps between the waterproof filler and the steel, and the steel STILL rusts! And the rust WILL push the filler away from the steel, giving you those nice bubbly things under the paint. Even if you try to seal up the backside, it's till not a sure thing! Another problem with those fillers is, that they tend to be harder, more brittle than the usual stuff. So on a flexible panel, they can crack more quickly.
Halleluia !!!!!!! I'm sure glad your posting this . Your responses are right on target. It is amazing that people continue to believe that there is a quick fix for poor repairs . This applies to painting as well as metal work.
Hey, I remember first seeing and using this "stuff" in the early 70s.... "Aluma-Lead" they called! "It's just like adding metal to your repair" they said! Survey say's "********!" It sanded hard, and given that it was held together with polyester resin, was no stronger than standard plastic filler! No filler, be it Aluma-Lead, Kitty Hair, Tiger Hair or $55.00 a gallon top -shelf preminum filler, will take the place of good metal work! S****ey Devils C.C. " Spending A Nation Into Generational Debt Is Not An Act Of Comp***ion !"
15 x 13. that's a big chunk. I say clean everything down to bare metal and start over unless you want to make these same repairs every 6 months.
I guess the guy should just sell his car and quit the hobby since he didn't get it right the first time. I think he is trying to learn from a lot of people who know what they are doing. I really like the H.A.M.B., but replies like this are rediculous. Some of us really need help, Pugsley
Put a little bluntly, perhaps, but CHOPOLDS' advice is right on the money. Asking questions on the HAMB is a very good beginning, but nothing is better than taking a good autobody cl*** or asking a qualified person to help you learn how to do it right. Hopefully there will be a HAMBer who lives close by who can help him out. Anybody in Fresno willing to give wandereryque a few hours of spare time?
Hmmm, We all learn from our mistakes.. asking questions here is good.. you get valuble answers. Ive seen custom/resto shops use way more than that.. even on TV.. sometimes those are misleading to some one that has the desire to do his own.. Got any pictures of the area in question?
Hey, Sometimes / most the time , the most valuable information is that most blunt! They're are some most valuable lessons that need to be learned, here. Tarting up, or sugarcoating the truth doesn't serve anyone! S****ey Devils C.C. " Spending A Nation Into Generational Debt Is Not An Act Of Comp***ion !"
Well he didn't get it right the first time, and he's asking how to load more filler into it! If he had asked why it cracked, or how to repair it correctly, then you'd have an arguement. In the world of bodywork, try, try again doesn't really apply. Either you do it right, or it fails.
First of all DONT use Bondo brand!! In my opinion it is the WORST mud on the market, pay a little extra and go with something good like RAGE Also incase of pinholes in the welds, use a skim coat of Duragl*** filler first, it ****s to sand, but it is waterproof and doesnt soak up moisture like most muds the Duragl*** will lay out better with a splash of a product called Supercharger, it kinda looks like honey
If you read the first post you will see the guy had done his first chop. Possibly he had a lot of warpage etc so he filled it rather than take the time to do it properly. It then fell out so he was asking how to redo the filler. The answers were simply that filling it is the wrong way to proceed. Metal repair is easier,cheaper and more satisfying than filling your lungs with polyester and coating the workplace with carcinogenic dust. There are dozens of sites right across the WWW telling anyone how to straighten metal so the use of filler is just for the lazy and those too lazy or arrogant to ask for advice or take on the advice given.
There aint no EASY way out, but the right way. Chopolds said it right! Filler was designed to fill a1/8 " depression. Sanded down level then primed . Anything else invites failure.
While as i loading my gun to shoot my self in the face I thought hey I may have did it wrong , I may not have the experience of 20 yrs of body work, and im not the worlds best welder ........**** IT I did it myself ,with no help from shops or nuthin in my garage, it's about the build, and learnin . even with my cracks my car still looked better then some **** ive seen at shows, so to all that gave advice and help, THANKS,to those who downed me ,I asked for Help atleast thats what i thought the H.A.M.B. was for . so I dust my self off and keep on workin, and ill still drive my car, not make it a 10 year project till its done right cause I build it to drive it.... ya estuvo
I'm with you....maybe you could use some help from someone more experienced but it was poorly worded...."if you didn't do it right the first time what makes you think you will do better the second time" or something along those lines is pure ****. I say we all learn from our mistakes and we will never learn anything without trying. Cl***es would be great but the school of hard knocks works OK too.
http://ruffrodders.com They'll love you over there. The advice was that you did it wrong, and you need to learn the right way. Learning how to load more bondo into a space previosly vacated by a 1 square foot chunk of bondo is not the right way. Do you want to learn to do it the right way? Or do you want to pound your chest some more?
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