Poly Putty vs. Plastic Filler vs. Short/Long Strand Filler

[turbocobra]

I am new to paint and body work, and have been doing a lot of reading and research, and have some videos on order, but confused about all the types of filler. Can someone provide a link or some details as to when each should be used?

I bought some evercoat metal glaze poly putty, but not sure if it is what I need, as the more I read, I see it is finishing putty that should go on last on top of any other fillers.

I have some repairs that I have made and welded in and coated with picklex. Which filler should be used first? I assume a short strand type filler?

When repairing a dent in good metal, once it is fairly straight, what is used first? Putty, or would you use a filler like Rage gold or extreme?

Thank you for your patience and help.

[Serge]

Yes Turbo...to fill in the welded drip patch you put on you need a waterproof filler such as milled glass or all metal. This is done to protect your topcoat from moisture that can seep from the underside of the welds through pinholes and other gaps. If moisture comes in contact with the back side of your repair and it has a regular poly filler the filler wiill swell and you get the infamous bubbles under the paint.

The idea is to create a moisture proof layer of fiberglass filler on the weld to protect every thing else you put on top. The first coat is fiberglass, then finish with regular filler, primer etc.

Any patch pannel weld would get the same treatment. Any pinholes you blast should get the same treatment. As soon as you have no protection to the underside of the metal, you need a coat of water proof filler. Regular filler is fine if the metal is not compromized (a simple dent...) and there is no way for moisture to get through to under the filler.

Be careful with Picklex, any acid treatment will prevent the fillers from sticking. Where you used picklex, make sure it is fully reacted (a few days) then sand off any whitish residue before applying the filler. You can skip the picklex if you spot blast and there is no rust left. Polyester resin does not like metal treatments, they disrupt the chemical reaction. So as a rule of thumb, no metal treatment or etch primer under filler. (No need to panic, just sand off the dried residue and give it a solvant wash and you should be allright.)

Also, spot blast the ground welds where there are craters and pits in the weld to make sure there is no welding residue there. You want bare metal even in the bottom of the weld craters and pits otherwise the filler won't stick to the botom of those cracks.

The fillers I use:

Link to the filler page from Len
http://autobodystore.net/Merchant2/m...tegory_Code=FM

Dyna-Glass....is what I use to fill in after welds and any hole that is through the metal.

Rage gold and Rage Extreme....These fillers are the cat's meow for regular filler work. This is not a finishing filler, its the regular filler. You would use that to create the shape after the milled glass or over any dent. You can get by with Rage Gold. I keep both as the Extreme version is a little thinner than the other. The Gold is a good all around filler.

Easy-Sand....is my finishing putty of choice. This is that last coat you use to get a smooth, pinhole free surface ready for primer.

Poly-Flex....is my finishing putty for flexible plastics...not a problem for your mustang...but your other beast has plastic bumpers on it....

Hope this helps.

[turbocobra]

Hope this helps.

Absolutely. Helps Alot, Thanks Serge.

2 followup questions.

1. I have a few areas that you see right on the top corner of the roof that are pitted from rust. I have spot blasted these, and it cleaned up nicely, should I pickelx it? What filler should be used over the pits? Dura Glass for this?

2. To confirm the steps over the welded areas:

- Glass filler
- Body filler (gold or extreme)
- Finishing putty (easy sand)
- 2K prime
- Paint

Thanks again for your help.

[Phil V]

I quit using polyester spot putty a couple years ago. What I would do in your case is apply the Duraglas/Marglas/bondoglas (whatever glas) over the welded areas. Don't even waste your time trying to get it flat. Just grind it or sand it a little past being level with the surrounding areas. Next I would use a regular lightweight filler like evercoat Z-grip (usually costs around $12 a gallon). Get your repair areas relatively flat sanding that filler. Finish of the repair area with some Rage Extreme instead of the polyester spot putty. Thats how I've been doing all my repairs for the last couple years. Polyester spot putty is upwards of $20 a quart while rage Extreme works just as well for me and costs about $30 a gallon. Much more cost effective and works just as well for me.

[turbocobra]

I quit using polyester spot putty a couple years ago. What I would do in your case is apply the Duraglas/Marglas/bondoglas (whatever glas) over the welded areas. Don't even waste your time trying to get it flat. Just grind it or sand it a little past being level with the surrounding areas. Next I would use a regular lightweight filler like evercoat Z-grip (usually costs around $12 a gallon). Get your repair areas relatively flat sanding that filler. Finish of the repair area with some Rage Extreme instead of the polyester spot putty. Thats how I've been doing all my repairs for the last couple years. Polyester spot putty is upwards of $20 a quart while rage Extreme works just as well for me and costs about $30 a gallon. Much more cost effective and works just as well for me.

Thanks Phil. Great Info.

What about the pitting in my roof (pics in other thread in rust repair section). Can I use the glas based filler for that, then rage extreme over the glas?

Or do I just need to use the rage extreme and be done with it?

[Serge]

Anytime there is a hole in the metal or there is a possibility of a hole or pinhole in the metal you should use glass as the first coat to fill those hole. So anytime you are filling a weld, a hole use duraglass or an equivalent milled glass filler.

Then you can use regular filler. Fillers come in many different price range and consistency but they basically all do the same thing. Rage extreme is very flowable and is probably half way between the consistency of regular filler and finishing filler...

[turbocobra]

Anytime there is a hole in the metal or there is a possibility of a hole or pinhole in the metal you should use glass as the first coat to fill those hole. So anytime you are filling a weld, a hole use duraglass or an equivalent milled glass filler.

Then you can use regular filler. Fillers come in many different price range and consistency but they basically all do the same thing. Rage extreme is very flowable and is probably half way between the consistency of regular filler and finishing filler...

OK, thanks. One last question. Should the glass filler be applied directly to metal, or should I do a coat of epoxy primer first?

[Serge]

I prefer putting fillers directly onto clean well scratched metal but others advocate the use of an epoxy primer...

I did a test a while back because of a debate that was going on and Len created a page with it...take a look if you want...

http://autobodystore.com/filler_&_epoxy.shtml

[turbocobra]

I prefer putting fillers directly onto clean well scratched metal but others advocate the use of an epoxy primer...

I did a test a while back because of a debate that was going on and Len created a page with it...take a look if you want...

http://autobodystore.com/filler_&_epoxy.shtml

Awesome writeup and great info Serge.

As a followup, if I apply glass and other fillers directly to metal, do I then use epoxy primer over filler, or only 2K primers over filler?

[emc2sign]

Serge and Phil...

Thank you for detailed answers and also thanks to all others willing to help out the next guy with their wisdom/experience. You are not just helping turbo out, you have just taught me everything this thread consists of. Down the road, I will help someone with the same material..


I just joined the forum today and I am very impressed with the information and its members.


Also, thanks to cobra for asking questions as well!!

Take care guys..