Filler debate

[Bas / NZ]

Please vote as to what you feel is best, seems to be 50 / 50 on this issue

[BusyKiwi]

I know it's a poll and all but just had to add my 2cents

I've been working with bog for about 30 years now, or 30 years since i started using it. I was always die hard bog on steel type then about 10 years ago we did some experiments with bogs (different grades of polyester, newtech ... ), the test wasn't actually for bog but rather how long bog over rust lasted - was what we thought (about 6months for bog, 12 for newtech, 3-18 for fibreglass ...)
Anyways, the panels preprimed actually stood up better off over time as the baremetal panels quite often displayed hand prints or fingers - the acid from the hands can create the start of rust. Also the metal can sweat, bog will soak up moisture.

Long story short I now always use primer first, doesn't have to be epoxy, etch primer is best.

Also another problem is primer isn't waterproof and a lot of people bag and prime and leave for a long time, the only real waterproof primer is an epoxy urethane.
It's not cheap, about $90 a litre and can't be primed later, has to be wet primed (a primer over a wet or soft coat)

[Bas / NZ]

Thanks David, I was told to use Resene's Dureopox 2k primer ( epoxy urethane), what brand of etch primer to you mean.

Bas

[Sammy]

I have to agree, etch primer then bog then I normally prime over the top of that.

[Merlin]

Hey how many people does it take before its a mass debate?

[rossie]

What about deoxidene, its a rust treatment.

[BusyKiwi]

I wouldn't bog over any rust treatment, once it's dry/hard sand it off with sandpaper, then etch then bog.

The rust stuff usually creates a skin, and over time this skin comes away from the metal.
Rust treatments don't really work, for it to work a little you need to coat both sides (usually impossible to get to underside), only real way to get rid of rust is to sand/soda/bead .. blast (both sides) or cut it out.
Think of a piece of wood with borer, you could wipe one edge down with kerosone which can kill them, bog up the holes, paint it and enjoy, but mean while the other side is still untreated and will continue to be eaten away.
Rust stuff like fisholene can work ok but only if spray on clean metals, is a waste of time putting it on rusty metal as it's a prevention thing not a killing thing, but rust is a different subject, bog is the subject on hand

[Bas / NZ]

Rust converter - no as it leaves a film, Rust killer Yes (tergo rust killer) wipe on wash off- but only good on mild surface rust, the kind of rust you can grind off and can't see it is there.

1/ Rust Killer as above
2/ Epoxy primer
3/ bog - filler
4/ primer
5/ Top coat

use a wax grease remover between next stages

This came from a mate in Germany that does restore work, did father in-laws car 10years ago still good today, so will follow this path myself, not to say it is the only way, but..........

Also ask about etch primer, he said yes but best suited to 1k primer...

Also said to use Epotec primmer (epoxy primer) by protec, reason, he said it can be sanded outside the window period very well unlike some brands.

[BusyKiwi]

Also depends on the type of primers/paints you use, some primers prefer to stick to etch primer rather than bog or steel, others have a type of etch built in.

[Bas / NZ]

Yes David I value your advise, given your talent and background as I am sure you have more know how and skill than most of us put together on here.

Just hard to get 100% yes on either way, so will go with the system I have seen, in the end if you have rust cut it out, I was talking about light surface rust only after a grind, in most cases the epoxy etc will do the job given the fact they contain rust inhibitors and is used as a sealer.