I hate bondo

So bondo has to be the most contriversial item since evolution was created. I am getting so sick of people telling me its good, its bad its good its bad. Then when I finally figure to give it a wirl and think its going good I've got a bunch of freaking pin holes. Finally, 20 layers latter, i'm only down to 80 grit scratch marks and some transition from metal to bondo. So heres the problem. Half the "experts" I talk to swear to prime the crap out of it then sand and repeat the process 4 or 5 times, or let the primer do the work. Others swear that the bondo has to be like "glass" before you can prime it. I'm torn, and the accumulation of me only being 17, the recent warm weather, and the menotany of sanding has made want to forget about the whole thing and take my 54 m38a1 for a spin. Help me out, give me some direction; I'm just a novice! Thanks...

 

I've certainly been there. Body work is my least favorite job, but it can also be the most rewarding. My first Jeep - a '79 CJ-7 - turned out okay, but required more skill than I had at that time. Several years later, I'm at it again with an early CJ-5. I don't think Bondo is the answer to everything, but it does work for small repairs, and general smoothifying.

I'm sure there are others with better methods, but mine (which does produce good results - not professional, but close) is as follows:

1. Shape it as much as you possibly can as it is drying. When it gets to a certain point - just beyond the doughy stage - stop fooling with it for awhile.

2. When it is hardened, use a random orbit sander with progressively finer grades of paper. I start with 60 grit, and work down to about 220 grit.

3. At this point it should "look" almost done. Prime it, and find out how bad it really is. I prime with a high-build primer, let it dry, and begin the endless touch-up and re-sanding process. I work my way to highest grit I have in my tool box. At this stage I sand by hand with a rubber sanding block.

4. The secret weapon I use is glazing compound. Bondo makes it, as do others I think. It has a more maleable or liquid consistency, and is very easy to sand. You can't use it to build up anything, but it does fill scratch marks, and aids in smoothing the transition from metal to bondo. Use an easy touch when sanding it - it comes off fast. This should also be sanded by hand with the block.

5. Prime again, and see if it worked. Usually, if you did a good job to this point, only a little more glazing compound will be needed - if anything - or some more primer, and a final sanding.

6. Some good Bondo tools are helpful - like different sized blades and scrapers. I like the wide metal scrapers, as they can also function as a useful straight edge for checking your reference on flat areas. Those cheese grater files are good too, but only in limited circumstances.

Thicker areas tend to "shrink" or sink a bit. If you have a few months before you put the final paint on it, try checking the spots where you put more than about an eighth of an inch depth on there. I've often found that I had to add a light skim over it some time later; don't know why this happens. It would be adviseable to not have to use more depth than an eighth of an inch, but I just can't seem to follow that rule all the time!

My biggest mistake this last time was to use cheap primer from the local parts store. I should have used a higher-quality primer. Be sure to plan ahead and think about what kind of top coat you want to use - brand and type. Then buy the right primer for that paint.

I hope this helps some. Mostly it seems to be a very slow process. This CJ took me about two years to finish what you are doing now. It looks good - but I too wish there had been an easier way apart from just replacing everything - which I didn't want to do anyway. Good luck; I'm sure other members will have some good ideas for you.

 

Blue Comet said just about everything I had typed and then for some odd reason, didn't post and I lost everthing. Sparky... what happened? (j/k)

Seriously though, I am 18 and did my 01 Dodge 1500 when I was 17. I learned the hard way how to do this, but I feel that I did pretty darn good for my very first time. I am happy with the results... I can show you pictures of my mistakes though so you know what it could look like when finished. I really don't feel like typing my short essay again so I will leave it at this. "If you can feel it, you can see it" E-mail me if you are interested and I will help you out.

 

1) Switch from Bondo to Evercoat. Glazing won't even be necessary.
2) If you have access to a compressor, buy yourself a "straight line" pneumatic sander. Buy sticky-back sandpaper by the roll, not the little 5 pack.
3) Use 80 grit to shape. Finish the filler with 340 grit. Prime with a quality urethane 2k. Primer will fill the 340 grit marks, but will leave 80 grit marks.
4) Read this article: http://southernpolyurethanes.com/perfect%20paint.htm

 

What he said . Go to a FLAPS that has a paint shop, and look at their body fillers. I'm one of the "I HATE BONDO" crowd . Evercoat and USC both make excellent fillers. A straight line sander is the easiest way to work with it. If you're on a budget, look for the longest board sander you can find. Jeeps have lots of long, flat panels that love long boards. I made my own once when I was in college...I got the longest concrete float I could find (which was actually incredibly flat) and put some heavy double sided tape on it. I got some HUGE belt sander belts, cut them in half and stuck them on. Being for a belt sander, they were extremely tough and lasted a long time.

For rough shaping, I have a poor abused Makita variable speed drill with a 5" sanding disk on it. I have to give Makita credit on this one...it's sanded several complete cars to bare metal, and sanded a ton of plastic and it's still going. The bearings make a lot of racket, but until it actually quites turning I'll keep using it .

For finer work, use your board. You can also get a cheapo 1/3 sheet finish sander. Not as accurate as the board, but it's reasonably fast and leaves things pretty smooth.

A $3 rubber sanding block can go a long way too. The big thing is just to try and keep things flat.

Oh, and forget the plastic spreaders you see for sale with the bondo...get a 6" steel drywall knife. It'll last forever, and give you MUCH better control when spreading plastic. It's nice and rigid, which makes it a lot easier to get it flat to start with. The better it is when you start sanding, the less work you have to do.

Hang in there...it'll get there. You'll be happy when it's done . It's funny...I always tell people "If you like sanding, you'll LOVE doing body work" R) .

 

I just finished applying this stuff and damn, I hate this sh*t. I keep getting the rough texture on the surface whenever I go over it with the knife. I think it's starting to set by the time i try to work it smooth. I should avoid going over it again once I get it fairly even. now it's all boogered and rough...

rant over

 

Jayhawk has it
My goal? be proud of all her war scars
But seriously, I hate bondo. Someone did it to my Jeep years ago, and they tried to fill all body lines Why? I don't know.
My attempt is to use little to NO bondo on her. JMO

 

Kind of an old thread. My recommendation still would be the same. From experience, only have one little nitpick to make:

I definitely would not recommend the filler-to-metal approach. Metal needs to be sealed to keep moisture out, and filler is a porous non-metal that keeps moisture in. The two in contact with each other = bad. My recommendation after experimenting both ways is to go with the Southern Poly approach outlined in the link above.

Basically, blast down to bare metal, clean with U-Pol or similar product, then immediately shoot 2 part epoxy to seal it. After that, proceed as listed above. There is no need to apply an etching agent if you sandblast because the media is the etching agent. If you don't blast (ie DA sanding), then I would recommend an etching agent, 2 part epoxy, and filler, in that order.

 

I used this walk thru http://www.hotrodders.com/articles/basic_bodywork.html

 

Get some of this stuff its in the body shop section of flaps.(extend)yes thats the name and it thin your bondo to spread realy nice and no air bubbles,

 

I have better luck with duraglass than bondo, and working about 12" at a time.

I also add a thin coat (like 1/16") of bondo, all but remove it all sanding and repeat as needed.

just don't be like whomever painted my jeep last and have over 1/2" of bondo in places and use it instead of adding new metal.

 

Lots of good information here. A couple of things I would add:

1) When I first saw this thread, I wondered if "Bondo" meant the brand or if it was generic term for body filler. Kind of like "Kleenex" is used to mean any brand of tissue. Evercoat is the way to go.

2) Don't use filler thicker than 1/8". I like to work the metal so I don't apply more than 1/16".

3) I use the plastic scrapers to apply the filler. When it has hardened to the point that I can leave a mark in it with my fingernail, I rough form it with a long half round Sureform "cheese grater". Then 36 grit sandpaper, followed by 80 grit, both on a long board by hand.

4) If you can, and one is available, take a bodywork class from your local Votech school. You'll be amazed at what you can learn at one.

tommy b

 

pinholes are caused by using too much hardner, rough surface is caused by it setting up too quickly " setting before you are done spreading" also more than likley too much hardner,or you are taking too much time spreading, quick question, does your mother make cakes? if so you are in luck, now this has got to have you wondering what the heck does cakes and body work have to do with each other, if you can get the hardner right you mother would be the best bondo spreader in the world, because its like putting the iceing on a cake, get her to bake a cake and teach you hopw to put the iceing on it, then you can throw that cheese grader looking thing in the trash primer will do alot of the "fine" work for you also, definetly use a good grade primer, and same brand type that your topcoat recomends or you will be back in here more upset than you are right now, nothing in this world like having your topcoat just crawl up off the jeep and wrinkle,BTDT

 

I guess I never watched my mom ice a cake. R)R)

tommy b