Sanding dash, need help!

**mazda3uzr** · 12-22-2004, 11:55 AM

well i use to have my lcd mounted on top of my dash but got pulled over a few times. now i moved it but have a huge hole on topf my my dash. i tried bonding it but a couple problems occured.

1) bondo had spots where it was not even. eve after i filled it and sanded it numerous times, it still had these little spots which looked like mini pot-holes. so obiously it looks like crap

2) when i was sanding it down, as soon as the sand paper went over my dash, it scraped it really bad. it looks like someone took a knife to my dash and started carving it.

i an guessing i am using the wrong kind of sandpaper or sanding method. can someone tell me how i can get rid of the little holes and what type of sandpaper i should be using?

**Quattro** · 12-22-2004, 12:05 PM

What type of bondo did you use to mold the lcd into your dash?

**joelw23** · 12-22-2004, 12:11 PM

what grit sandpaper are you using????

pics?????

**Scouse Monkey** · 12-22-2004, 01:59 PM

1. you are just gonna have to keep sanding and smoothing over with more filler
2.try fine wet and try and do it in the sink with washing up liquid

**Scouse Monkey** · 12-22-2004, 02:12 PM

Also are you using a hard/semi hard block behind your sand paper? don't jsut use fingers they are too soft and you will get waves.

**mazda3uzr** · 12-22-2004, 02:29 PM

for the bondo, i am using the lightweight filler which comes with the small tube of hardener and has a pic of an old mustang on the container. for the sandpaper, i beleive i am using 400 but it could be 200. again, the lcd is no longer there, i am just trying to fill the hole where the lcd use to be to get it back to stock

**Quattro** · 12-22-2004, 02:37 PM

to fill the hole you should have first used something stronger like reinforced bondo or Poxy weld. This would fill in the hole much better, then you should have used the lightweight filler to smooth it out. The lightweight filler by it self may being to crack in a short period of time.

**2.0i** · 12-22-2004, 03:41 PM

The have a bondo glaze that comes in a tube. It's made for imperfections like you're describing. And I agree with using a sanding block

**RedGTiVR6** · 12-22-2004, 03:57 PM

I'm confused, did you think that running 200 or 400 grit sand paper wouldn't ruin your dash?

also, are you planning on finishing off the bondo to match the dash at all?

as for the holes: you just need to put a few more layers on with a spreader, did you use a spreader in the first place? then sand with a block backing the paper. Use rough stuff for a few passes to knock off the high points then go to something like 320 for a bit then on to 600 then 2000 or so for the finish...

I could be way off but what is your dash made of? is it plastic or vinyl? I just don't understand using bondo on your dash unless it's a HARD plastic dash.....*scratches head*

also, did you throughly clean the surface of the dash and rough it up before you applied the bondo?

I agree with joelw23....have any pics?

**Altimat** · 12-22-2004, 05:43 PM

Make sure the dash part is ABS and not Polyolefin. Polyolefin requires an adhesion promoter for anything to stick to it. Its characteristics are that when you grind it it melts very easily, and sand scratches are very deep. Sandpaper doesn't really actually sand material off very well, it mostly just makes deep scratches. The back of the part should indicate the plastic type. Look for ABS or PP.