A Couple of Epoxy and Filler Questions...

[Misterg]

Do I need to key fresh epoxy primer before I put filler over it?

(Specifically Lechler 29107 with Upol 'Fantastic' filler or Dolphin Glaze.)

I plan on another coat of epoxy over the top of the filler once the whole panel is done. How long can I leave areas of sanded filler without painting it and not risk getting problems later on? (Unheated, but dry garage.)

Ta.

 

[Morris]

I always key epoxy for filler.
Coat sanded filler with epoxy asap.

 

[Misterg]

Coat sanded filler with epoxy asap.

How long can ASAP be? Would a week be too long?

I'm just thinking that I don't want to be mixing up and spraying small patches of epoxy every day...

 

[steveo3002]

would it hurt you to prime each panel as its ready ? thats what i would do , surely you can fill and sand at least one or two panels in a day

 

[ajlelectronics]

Do I need to key fresh epoxy primer before I put filler over it?

Not absolutely essential if under 24 hours or other window suggested by the TDS. However I would always allow it to cure properly, flat it to 180 and fill on the same day that you intend to overcoat. You have to flat the rest of it anyway, so it seems a bit pointless not to. Besides which, flatting will take off the "shine" and expose the areas which need stopping.

(Specifically Lechler 29107 with Upol 'Fantastic' filler or Dolphin Glaze.)

I plan on another coat of epoxy over the top of the filler once the whole panel is done. How long can I leave areas of sanded filler without painting it and not risk getting problems later on? (Unheated, but dry garage.)

Polyester filler is going to absorb moisture, so fill and overcoat the same day.

 

[Misterg]

surely you can fill and sand at least one or two panels in a day

We'll see!

It was more the hassle & wastage of mixing / cleaning out the gun , etc, but the message is clear.

 

[Misterg]

You have to flat the rest of it anyway, so it seems a bit pointless not to

Thanks - I was thinking of the areas that I've repaired that will definitely need a skim (at least) of filler. My intention was to get them somewhere close before trying to block out the rest of the panel, but the advice is clear.

 

[Maxakarudy]

I know all the sprayers are gonna roll their eyes when I say rolling or brushing a bit of paint is so "Old school", but I still stand by it today.
When you are in early stages of repair/restoration work, you are not doing it like a full time job, you might have just a couple of hours on a big project
once or twice a week, so convenience is a big factor to consider.
Yes always key up any primer even if data sheets say otherwise, YOU pay the price for stuff falling of later.
When you are at the point when all the prep work is done, then DA sand everything smooth with 180g and spray apply your finally coats of epoxy.
If you've left filler exposed overnight, use a hot air gun to dry it off before priming.

 

[steveo3002]

We'll see!

It was more the hassle & wastage of mixing / cleaning out the gun , etc, but the message is clear.

id say its not a bad thing , trying to do a whole car in one go can get a bit overwhelming , vs priming one or two panels at the end of the day makes it feel like you are getting somewhere

and yeah if its a small bit why not brush it , then sand and spray it again when you have the gun out