Sanding filler

[cliff366]

Hi chaps I've got to sand large areas of filler flat just looking on tips or the best way to attack it as what I've done so far you can still see its bumpy even tho I've used the biggest block I've got don't help that it's on a curve to lol
Attached some pics to show the main bit I'm struggling with
Cheers

 

[steveo3002]

flat blocks and lots of guide coat , use a fairly coarse grit until its taking shape , finer stuff will ride over the bumps rather than slice them off

 

[cliff366]

Another way I thought of doing it was to cut 2 strips of 0.8 sheet a few inchs wide then put one top and bottom then rule of them then remove and fill but did worry it may crack over time along the 2 joins ??

 

[steveo3002]

not sure im with you there cliff ? can you explain again?

 

[cliff366]

Sorry cut a strip off 0.8 to run all the way round under the gutter so it's flat against the back
same on the bottom fix in place then fill in between so should be 0.8 depth in the middle
Fill that area and rule of the top and bottom remove the 2 strips and fill the areas that was missed as the strips was there
I suppose the best way to explain is like when your concreating and you set your shuttering level run of each side with a stright edge
Hope that helps lol

 

[steveo3002]

hmm yeah i understand ,not how id do it

does take a bit of hard work to get stuff like that right , also be mindfull that its easy to keep putting more and more on when its not needed

once you think its getting there lash a coat of rattle can gloss on and inspect it for ripples and defects while its still wet , then wipe off and carry on

 

[cliff366]

Ok cool cheers I will give if a go by eye and see what happens worst case I'll have one arm bigger than the other lol

 

[colnerov]

Load filler on and use a perspex number plate as a wide spreader to take it off the high spots and leave the low filled.

 

[norsa]

Load filler on and use a perspex number plate as a wide spreader to take it off the high spots and leave the low filled.

Very useful technique on large panels. Probably worth investing in a dual action sander to get the shape right, then block it on your final skim fill over guide coat.
Nick

 

[norsa]

something like this
http://www.diy.com/departments/bosch-corded-220w-random-orbit-sander-pex-220-a/196773_BQ.prd

 

[cliff366]

Cheers I've got a da but thought I'd prob be better using a large block so I was hopfully riding over the hollows easier

 

[the snooper]

id use the da to get the shape you want quickly and as close as possible then start with the block, otherwise you'll be there for ever just getting the shape you want

 

[keithski122]

When I did the roof of my beetle(after welding up the sunroof hole) I used a number plate for applying the filler and a lot of sanding with a 16 x 3 long block with something like 80 grit paper.Had to reapply filler lots of times and ended up doing virtually the whole roof.Dolphin glazed it after the filler work.Can't tell there ever was a sunroof in it now.

 

[langy]

Long block is the thing to use, use it backwards and forwards at an angle

 

[cliff366]

Cheers guys will give it a go tomorrow hopfully if I get any spare time