Newbie cant get filler smooth

[BIGMIKE]

At the minute Iam working on an old astra convertible which we're using for a banger rally across europe in July. To get it ready for the mot Ive had to sort out a few holes in the sills and inner wheel arch. Now in fairness this car only has to pass an mot and not be pretty but I thought it would be good to practice my welding and metal working skills, then try and paint the repairs as well as i could, again just to practise really.
Where Ive welded in a new piece of metal on the quarter panel/arch area ive had to fill and smooth it but I just cant seem to get the filler smooth, I always end up with dimples(i assume they are air bubbles or something), Ive tryed resanding,filling again but still end up with some somewhere else. I thought high build primer might help so bought some and probably did help a bit but still obvious if you look. Is there something Iam missing or just not being patient enough and you need to do the whole process a few times???

I know Iam not good at being patient thats why Ive got a run in my new paint today! I assume I can just flat this down with 1200 paper before applying the lacquer?
As Iam already part way through painting the Astra repairs now Iam not gone a bother going back to sort these dimples in the filler but really wanted to know for future as Iam hoping to repaint my old kit car this year and thats gone a need a lot of filling so wanted to do as good a job as I can really.
Any advice appreciated
Mike

 

[pedrobedro]

What filler are you using? Some leave pinholes in the surface and are more for large area filling than small repairs. Use an easy sand filler and don't put it on more than a couple of mm thick, rub down with 80grit paper and when you are near level put a fine skim on and rub with finer papers before you prime. Impatience is not a good thing with filler and paint.

 

[BIGMIKE]

I had just been using a small tin of body repair filler a mate had given me that he hadn't used, did seem quite thick and not very easy to smooth out. Ive now bought a large tin of isopon P38 for using on the kitcar, will this stuff be better?
I certainly realise bodywork is all about patience, no wonder theres so many bad repairs out there!

 

[langy]

Get yourself a tin of Upol fantastic, you won't find an easier filler to use, P38 is old hat really, i havn't used it for 20 odd years.
And use a block.

 

[piman]

Hello Mike,

the other thing you can use is spot putty, if you don't want to go and get a different filler. Why are you putting clear on, just an extra job?

Alec

 

[tux]

Old filler doesn't help either. I have found that it encourages pinholes, just like you describe.
As above really, fresh filler, no more than 2 or 3 mm skim at a time. If you still have issues with pinholes, just foll them with some stopper/knifing putty.

 

[pleej]

finishing filler will get shut of the pin holes or dolphin glaze is amazing stuff

 

[BIGMIKE]

Thanks for the replys, is upol a lot smoother to apply? I was putting it on thicker than 3mm In places.
As I said Iam not to bothered about going back and sorting the Astra just want to learn were Iam going wrong so I can get the old Kit car write when I do that. The only thing Iam going to do with the Astra is try and sort the run out again just to practise and learn what to do. A run and some dimples under the paint are the least of this cars worries
As for the clear coat, I thought I had to as its a dark metallic red, thought it would match slightly better???

 

[langy]

Your problem is your using old filler that has dried out Mike, Filler should have the lid on as often as possible, plus the modern fillers are light years ahead of the old ones.
Upol make a cheap filler called Big Easy, It pinholes and sinks like mad, thats what cheap filler does i'm afraid, for a few pounds more the job is better and easier

 

[Chipper]

Had to use P38 recently, couldn't get anything else local. Horrible stuff, soaks up primer. Ended up skimming with Dolphin Glaze as above, which made it much better.

 

[BIGMIKE]

Well looks like its the old buy cheap buy twice then! I'll get some better filler for when I tackle the kit car bodywork. For now the Astra repair looks like it will turn out ok for what I need and its been good to have a play and a bit of a practice

 

[scotty-stoke]

has anyone used the stevens make? its like to trying to sand concrete down.