View Full Version : will my filler absorb moisture?
05-26-2006, 05:30 PM
I'm new to this filler thing, and I just started working on my first major panel job. I applied Picklex 20 to the bare metel, then scuffed it when dry and applied Rage over it. I cut that down a little too far, cutting through the Picklex in the process, then applied another coat over the first. Thus, I have some filler applied over bare metal that is not protected by Picklex. Can I safely wait a few weeks before applying epoxy over the filler, or will it absorb water? The car is in a non-heated garage in Virginia. There is never any condensation inside the garage, but the air is often humid here. It would be far more convenient if I could wait!
Also, I was planning to re-treat the bare metal around the filler with Picklex, using a rag to apply so I don't get too much on the filler. Is this advisable?
05-26-2006, 10:13 PM
Any polyester filler should be applied direct to the properly sanded metal. Just give the metal a good scratch ( 80 grit is fine ) and apply your filler. Now, what bothers me about your filler job is that it is sitting on some picklex...that would make me uncomfortable. I think its even on the picklex instructions that it should not be used under filler...
Picklex should also be used with caution under any acid sensitive epoxy primers. The acid environment created by picklex prevents some polyseters and epoxies from attaining full cure....
Moisture in the air should not affect your filler much, I would not sweat it...however, regular filler does not like water. So, if there is any chance that your filler will see water in it's life from a hole in the metal that would let water touch the filler or from small pinholes in a weld then you should switch filler and use a milled glass filler or some all metal filler. Those fillers are water proof and will not swell when wet.
Hope this helps...
05-28-2006, 07:06 PM
Serge, There are no "water proof" polyester fillers. It may use that word on the label, but call the companies tech department, I did, at least Evercoats. They said, the "water proof" means AFTER priming and painting. :) No kidding, after it is sealed with primer and paint it is "water proof". If you check the MSDS on these products you will see that they still have talc, just like "regular" fillers and WILL absorb water.
John, you really shouldn't be applying that Picklex around the filler, it is bound to get under it and cause big problems. First off, if you are not able to prime something for a few days, epoxy prime the bare metal and then apply the filler over the epoxy. This is a STANDARD of the industry and recommended by many manufacturers. How ever, if you don't choose to do this and have bare metal spots around the filler it should simply be primed as soon as possible. If you are working in a dry shop and you don't have high humitity like in the southern states leaving it a few day is no big deal at all. If you don't see any discoloration from rust it is likely there is none to speak of and all is good. Heck, here in sunny California cars sit in bare metal for months at a time. It really depends on the time of year and the area you are in.
I don't like the idea of applying the plastic filler over the Picklex at all. Have you checked into that here on the site with Len? It may be ok, I have never heard of one way or the other. But it doesn't sound like a good idea to me, as Serge mentioned.
05-28-2006, 07:48 PM
Thanks, Serge and MartinSR! I've actually gone back through my "personal archives" that I started a couple of years ago, and found that I had cut and pasted the following quote from Len:
"Filler can be applied direct to metal, over Picklex and over epoxy primer but not over etch primer. I usually apply mine direct to metal. Some folks apply filler over 80 scratch but I usually put a 24 or 36 scratch in the metal prior to filler.
You can apply etch or epoxy primer OVER filler but not Picklex 20. The Picklex will soak into the filler and not dry properly. I try to avoid applying Picklex on top of anything but bare metal. When applying Picklex in areas of filler or other materials it's best to apply it with a brush so that you have tight control over where it goes. "
I do live in a very humid place (Virginia), so I'm a little worried about the moisture absorption issue. If necessary I'll grind it all down to bare metal again. I don't want to have to do this over again!
05-28-2006, 09:49 PM
John, I would seriously think about spraying epoxy primer first prior to the filler.
05-28-2006, 10:30 PM
Gee...Never thought to look at the MDS...However, it does much better than regular filler when exposed to water...Don't know why...and allmetal is even better, but I hate sanding it...
I had done a test a while back and dunked blobs of different fillers in a bucket of water and the milled glass did very well...regular filler did not...I am going to have to redo this test...I'll keep the blobs in closed jars to see how long it takes the milled glass to blow up...
I am going to start looking at the marine stuff now...
Thanks for the tip...
05-29-2006, 10:12 AM
To be safe, I'll go with your suggestion to put epoxy down first. I've actually mentioned this to the paint supplier in town, and he looked at me like I had two heads, and said that epoxy primers have adesion problems, and that what I need is an etch primer. I called a place in another town nearby, and the guy there agreed that epoxy direct to metal would be an option, but he still recommended an etch. So basically, I'm going to have to have my ducks in a row when I go to buy my primers and paint so I can tell THEM what I want rather than asking their advice. I'm thinking: epoxy, filler, epoxy, 2k, basecoat, clearcoat. I'm not sure if the second coat of epoxy is necessary.
Are all epoxies the same? Are some better than others for my purpose? The local supplier deals in BASF products (I think he recommended RM for my project, which is not a show car, but not a junker either). Should I buy Kirker? I would have to have it delivered, since there is no Kirker dealer in the area.
Any advice much appreciated!
05-29-2006, 10:25 AM
There are differences in epoxies and to tell you the truth I don't have experiance with a lot of brands as some other guys here do so I say start a new thread "What epoxy should I use".
I personally don't see why a second application of epoxy over the filler is a good idea either. Urethane primer (commonly called "2K" however EVERY product that uses a hardner INCLUDING epoxy is a "2K") over the filler is my choice.
I don't know where your store guy would get that epoxies have "adhesion problems". They have always been known for their great adhesion qualities. He has probably had some problems with the brand he sells (still probably user error) and he is gun shy.
05-29-2006, 12:06 PM
John, The Kirker epoxy primer is a good primer several guys here use it and it sands well if needed also. to get a good deal on it go to ebay there it sells for about $77.00 delievered for 2 sprayable gals. Also if you have already used the Picklex just scuff it and shoot the epoxy over it.
I'm no way associated with this company just passing on what I believe to be a good deal .
05-29-2006, 02:07 PM
Thanks again to everyone who responded, and thanks to Earl for directing me to Ebay. I've heard good things about Enduro Prime, and I believe that it is iso-free as well (bonus!).
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