12 replies to this topic

[spud]

Hi,

I'm prepping my mini for respraying at the moment and I'm wanting to know the best way to fill and sand minor dents etc. I'm wasting a lot of time by sanding and refilling etc as I always end up with slight ripples etc in the filler or I end up sanding off too much filler leaving a slight depression which then needs refilling :'(
I am sanding with wet and dry and mainly using the palm of my hand lightly to get the surface level - but it just never seems to happen.
It appears that all the surfaces are convex and with different radii so I can't make up a sanding block to match the surface!!

Any pointers would be appreciated,

spud.

[Mini 360]

Well from what i have read your doing it all right! Maybe try sanding in a circular motion which should!....stop it from rippling because this occurs when your fingers start to make ripples with goin over the same bit too much.

Hope this helps and remember practice makes perfect!

[JD8891]

why not try using a foam sanding block? it will match the suface but will stay flat i think.
JD

[Woody]

You should allways use a block even on convex surfaces .
right ,remove paint from area to be filled and an inch all around
mix filler and apply and aim to leave it slightly proud ,
block this down (80grit DRY) when the surface is allmost right give it a fine coat of aerasole black paint and continue to block down (this is called a guide coat) now you can actuly see where is low
DO NOT RUB FILLER WET !!!!!
When the shape is right it is time to get the surface nice for this you need stoper
mix stoper and apply over the filler in a fine layer
block down this with 180 grit paper and guide coat
should now be ready for primer
when primered , guide coat and block with 800 grade paper wet (or dry with 400)

[spud]

Thanks everyone

I'll take your recommendations on board!

What is special about 'stopper'? Is it just a super fine filler?

Cheers,

spud.

[DenZal]

when working in a body shop they told me to always sand diagonally, and never try digging little bits to make them lower just keep the block flat, keep going diagonally and move it about a bit ...my filling an sanding still sux tho lol

[Mini 360]

Why should you not rub it down wet?

[Retro_10s]

Why should you not rub it down wet?

because filler is one of the most absorbant materials man has created!!! if you rub down filler wet it will absorb moisture and it will soak thorugh to the metal, then when you think it's dry and paint over it, the moisture will try to escape, it will come back through the filler and lift off your fresh paint, but worse it WILL rot through the metal you fillered over.

so it's fairly important.

Edited by Retro_10s, 25 October 2006 - 07:29 PM.

[Woody]

what HE SAID !!!!

[Boy Racer]

Why should you not rub it down wet?

because filler is one of the most absorbant materials man has created!!! if you rub down filler wet it will absorb moisture and it will soak thorugh to the metal, then when you think it's dry and paint over it, the moisture will try to escape, it will come back through the filler and lift off your fresh paint, but worse it WILL rot through the metal you fillered over.

so it's fairly important.

I thought p38 was non absorbent? I know that polyfilla is absorbent but i though p38 was quite waterproof??

[Mini 360]

Why should you not rub it down wet?

because filler is one of the most absorbant materials man has created!!! if you rub down filler wet it will absorb moisture and it will soak thorugh to the metal, then when you think it's dry and paint over it, the moisture will try to escape, it will come back through the filler and lift off your fresh paint, but worse it WILL rot through the metal you fillered over.

so it's fairly important.

I thought p38 was non absorbent? I know that polyfilla is absorbent but i though p38 was quite waterproof??

^^^Thats why I asked i thought the same^^^

[Retro_10s]

Personally I wouldn't rub down ANY filler wet, regardless of what it sais on the tin,... better to be safe than sorry, I'm not saying i know better than the manufacturers or anything lol, but through my own stupid mistakes i've learned to be super cautious about stuff like this, and it has paid off.

But by all means, if P38 claims to be waterproof, go for it.

[midridge2]

rubbing down wet is fine, just make sure you dry the area with a heat gun befre you prime it.
ive worked as a panel beater for 35+ years and every garage ive worked in all painters and body bashers have rubbed down wet for the finner grades of paper and never had a prob with water comming out as it was all dried out first.