I hate Bondo!

gatordad

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Been working on my Multiwilliams Defender, repairing the base and fixing the coin opening to change it from black door to stainless steel,

It's a pain sanding filling , sanding, filling and sanding again. This cab is taking forever to get to paint, I am hoping this weekend to prime it, we will see................
 
Just take your time, you're doing it right. I usually go through 4 or 5 cycles of bondo/sanding before I'm happy with it.
 
Sometimes it's hard to get a good technique with bondo. Ideally, you should apply one coat that is exactly the right fill or slightly under ... sand just a bit to get it cleaned up so that it's a good "base" that is about 80-90% right with no high spots (everything the right level or a little low). Then, make a second application that brings that base up to just a little higher than level. This gets sanded to level and you are done.

There might be a case where you have some small bubble holes to fill in but those will be minimal if you mix the bondo by "folding in" with your spreader and not swirling with a stick or screwdriver. Doing that just adds air pockets causing you trouble later. The spreader method keeps air out.

When I started, I'd have WWAAAYYYY too much bondo and sand forever. I was thinking that I'd apply bondo just once so I better get enough on there and shape it with the sandpaper. Wrong. You want to be an expert with the spreader, get it very close with that and sandpaper is just for a little leveling. If you really have bad technique and apply too much, get a cheese grater type bondo tool to get it down fast. That's a bit of a hack method but it'll get it back down to level so you can try again to be more precise. Alternatively, get some really low grit paper (I've even used a grinder with 36 grit because I got so crazy :eek:) and cut it down fast, then back down to something more reasonable to continue getting to level.

Stolen from a website: Sandpaper grits are largely a matter of preference. Here are some basic guidelines:
24 to 36-grit for roughing out the filler with an air file sander or hand board
60 to 80-grit for smoothing out the rough scratches from the previous operation and shaping finer contours
80 to 180-grit for further smoothing in preparation for high-build catalyzed primers (with hardener), or 240 to 320-grit for lacquer-based (non-catalyzed) primers
320 to 600-grit for final sanding prep before paint, following the manufacturer's guidelines on their product information sheet

You'll get dust everywhere from even just a little sanding but if you have a 1" pile of dust on the floor you've applied too much!

Keep working! It'll get there!!
 
Next time skip the bondo and use Evercoat #7. It's much smoother and dries harder and faster than Bondo. I usually only need 2 applications to get a good finish.
 
Next time skip the bondo and use Evercoat #7. It's much smoother and dries harder and faster than Bondo. I usually only need 2 applications to get a good finish.

+1 for skipping the bondo.Haven't tried Evercoat but I've been using Epoxy Putty instead of bondo.Much easier and safer to use,plus it hardens pretty quickly.Worked great on the bottom of one of my cabs that had a lot of chunks missing.
 
Almost forgot...you know what easily removes Bondo from any surface?

This......

































chuck-norris-0021.jpg
 
Another thing about Bondo:

If you have a large chunk to fill, or a corner edge, it's best to use less of the red hardener than normal. Takes longer to dry but fills in and levels out better. The more red hardener you use the quicker it will dry and the easier it is to get bubbles. Takes some experimentation but you will eventually find a mix you like.

Another thing I've learned is to use scrap plexi to form the edges. Some people use large clamps to hold them down but I've been successful with duct tape. The plexi separates easily from the bondo and can be scraped off and used again.

3 or 4 bondo / sanding iterations is all I've needed, but sometimes for larger areas it takes more.

Most importantly when sanding bondo use a respirator or at least a N95 dust mask. The dust is nasty and you don't want it in your lungs or nose.
 
Use Bondo for the structural repair. Then Evercoat Metal Glaze for a smooth finish and primer after that.
 
Been working on my Multiwilliams Defender, repairing the base and fixing the coin opening to change it from black door to stainless steel,

It's a pain sanding filling , sanding, filling and sanding again. This cab is taking forever to get to paint, I am hoping this weekend to prime it, we will see................

mike, your doing it all wrong man..


step one:
l_0ba5977a0f4ae4e50379eae1faf8e744.jpg


step two:
l_0f4692a8010248412bc88c6ec547b1de.jpg


Then in a bondo fume buzzed state, sand away happily.

If you stop seeing your pet unicorns and pink elephants, repeat steo one as necessary :D
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seriously,

heh.. yeah filler is a bieotch sometimes, done right its easy.

Dont use bondo brand bondo. that krap sucks. Its good for rough filling but it sands like ass. Get professioal auto body filler from a reputable parts store (not autozone)

sanding is easy as hell with a da sander(dual action) i have a 6 inch and 8 inch air powered das and they power right through the filler like frizz smoking a J .


Evercoat makes fine fillers.. and yes the name is misleading but evercoats metal glaze is basically like spot putty.. goes on super smooth and sands super easy, but its made as a fine finishing product, its not good for filling big holes and its very runny.

so to recap fill with regular body filler.

to make life easier the last coat or two shoudl be spot putty/metal glaze

youll be done in no time.

I can feel your pain. Ive been doing bodywork on my old truck on and off for several months now. It feels like im never gonna finish the damn thing. But dont worry, youll get there
 
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Caddy thats crazy!

Just finished sanding it down today, looks pretty good, got to clean her up and prime it, I am going to see how one small area comes out after the primer, may have to fix just one more spot.

Stencils came on Monday so the pace has quickened
 
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