91 cb7 rust

[SeaHook]

Never use Bondo by 3m. Fillers are not their strong point.

If you choose to use any body filler as a clay to shape body panels then you must go with a waterproof one such as tiger hair or kitty hair to gain a shape. They are made by evercoat and have fiberglass reinforcement.

Just make sure that you cut out any loose rust. Grind down any surface rust and neutralize the rust with rust-mort by SEM.

Glaze with a glazing putty and prime with a 2k primer. No need to mention the sanding and prep-all.

I've used tiger hair on extreme dents with out a single problem other than it is a bitch to sand.

[cuate01221]

Never use Bondo by 3m. Fillers are not their strong point.

If you choose to use any body filler as a clay to shape body panels then you must go with a waterproof one such as tiger hair or kitty hair to gain a shape. They are made by evercoat and have fiberglass reinforcement.

Just make sure that you cut out any loose rust. Grind down any surface rust and neutralize the rust with rust-mort by SEM.

Glaze with a glazing putty and prime with a 2k primer. No need to mention the sanding and prep-all.

I've used tiger hair on extreme dents with out a single problem other than it is a bitch to sand.

This is still completely wrong! You need to put metal there! Sure the fiberglass will last longer than bodyfiller, but it doesn't bring back the cars structural integrity that the body is made to have.

Lets put it this way. Lets say you listen to SeaHook and cut out all of your rust(way more than you might think once you start looking into it) and just put fiberglass in it's position. Although the car will look great if you do a good job, it will not be structurally sound anymore. You will not have the proper collapse zones to absorb the energy when you are rear ended, and your car will now be weaker and probably just fold like an "accord"ion. Anybody you have in the back seat will probably be either killed or seriously injured, and can sue you for not making your car structurally sound.

[soybean]

because you covered the hole with body filler.... We all know body filler absorbs water/moister and even if you paint it, the existing rust will just continue to spread.... body filler is only supposed to be used to level minor surface imperfections. Not used as clay to mold things.

Well, I don't believe it absorbs moisture out of the air but I might apply primer and paint to it on the inside of the trunk as a way of sealing it there. And, on the underside, where the direct exposure to moisture can occur when driving on wet roads, I'll use undercoating to thoroughly seal it. I took this approach on a much smaller area in a different part of the car in 2010 and that's held up OK.

Soybean, did you look at the "Rescuing Ruby" thread? That is a more appropriate way to deal with the rust damage you have (not just because it is my thread). Looks like you even have almost the same car.

Yes, I would agree that's the ideal way to deal with the rust issue. But, it's also much, much more costly. My objective is to stop the entrance of water into the trunk and substantially impede continued rusting. I think this repair will accomplish that. Since this area is hidden, the cosmetic appearance of the repair is not important.

This is still completely wrong! You need to put metal there! Sure the fiberglass will last longer than bodyfiller, but it doesn't bring back the cars structural integrity that the body is made to have.

Lets put it this way. Lets say you listen to SeaHook and cut out all of your rust(way more than you might think once you start looking into it) and just put fiberglass in it's position. Although the car will look great if you do a good job, it will not be structurally sound anymore. You will not have the proper collapse zones to absorb the energy when you are rear ended, and your car will now be weaker and probably just fold like an "accord"ion. Anybody you have in the back seat will probably be either killed or seriously injured, and can sue you for not making your car structurally sound.

Structural integrity is a complete non-issue in my view. I'm not saying it's not important; I'm saying it's just insignificant in this case; by the way, I rarely have passengers in the back seat. The trunk floor area where the large hole occurred is not a load-bearing part of the floor, as far as hauling any cargo in concerned, since the hole is in an area hidden by the trunk liner. Still, I think I will do a periodic inspection to see whether any cracking of the filler has occurred; I am aware that, with uni-body construction, any flexing of the body might affect the patched area and the body filler may crack since it does not flex.

I have not removed the right trunk liner and fully assessed that side yet. But, I believe that side is also allowing some water to get into the trunk. I may do some more research on alternative materials to use there. The only welding I intend to have done is to weld an outer molded panel on the right side.

[cuate01221]

It will still make your car less structurally sound than it was out of the factory is all I'm saying. I just hate it when people make patches with body filler. A cheap welder and some sheet metal is not that expensive and will be the right way to do it and longest lasting as well.

[SeaHook]

Sorry for bringing this back up.

I was only stating that bondo is not a great product. Meanwhile mentioned many of the other chemicals needed to properly treat rust. There is always more rust than you can see and the best way to fix it is replace it with fresh metal. Sheet metal is cheap and welders are everywhere.

Cuate01221, you are right about the metal and crumple zones. It is a safety problem as well as harder to fix when filler is used in place of metal should a problem re-rise.

If you choose to use the filler to fix small holes then go with a oil based filler that has glass strands in it. They are water proof. Bondo is polyester based and will absorb any water it can.