blakep82
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posted on 14/6/12 at 08:04 PM |
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best sander for body work?
trying to prep the body for painting, and i bought a cheap tesco value flat sander.
would i have been better off with something like this?
eBay Item
i'm finding that even with an 80grit paper, the flat sander is taking ages to key the surface, and when it does there's big scratches, and
its still shiney from the gel coat between scratches.
wonder if a da sander will give a better result, with say 120 (or higher) grit?
i've got a big compressor, so air won't be a problem, or if there's an electric one as cheap?
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tomgregory2000
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posted on 14/6/12 at 08:20 PM |
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I would go for a DA but I would buy an electric one unless you want to do it wet
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cliftyhanger
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posted on 14/6/12 at 08:21 PM |
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Tried a DA sanader on my 3hp compressor and it struggled big time.
A leccy one would be a safer bet.
However, what are you going to do with 80 grit scratches prior to spraying? I reckon 320 would be more appropriate or even finer.
You can also buy matting paste by farecla,
http://www.fareclaonline.co.uk/acatalog/Farecla_Preparation.html
use it with a proper polisher (needn't be expensive) and will be useful later
Silverline Sander Polisher 180mm 1200W | eBay
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blakep82
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posted on 14/6/12 at 08:26 PM |
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the cheapest electric one i can find is £75, which is about £80 more than i've got...
i probably will do wet sanding with it.
clifty, i started with 120 paper on the sander i bought, and it wouldn't take the shine off the gel coat at all. in fact, i swear it was getting
shinier! thats why i was thinking something with a more agressive action, but finer paper might be better?
i ideally wanted to do it 400 grit paper before spraying filler primer, but since the 120 didn't make a mark, i went for 80 to take the shine
off, hoping that would help start it off
i guess air/electric is pretty much a personal choice. air tools you can adjust the pressure to low it down if needed i guess
my compressor is 3hp, 150l tank, 14cfm free air etc, should be up to the job i guess
but regardless of air/electric, a DA sander is the right one to go for then?
[Edited on 14/6/12 by blakep82]
________________________
IVA manual link http://www.businesslink.gov.uk/bdotg/action/detail?type=RESOURCES&itemId=1081997083
don't write OT on a new thread title, you're creating the topic, everything you write is very much ON topic!
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cliftyhanger
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posted on 14/6/12 at 09:04 PM |
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probably, but I don't understand why the gel coat isnt getting flatted. Maybe it is just too coarse (I use 80 grit on rough woodwork, and have
used it to shape filler, but never to prepare for paint)
If the gel coat just needs the shine taken off, I really would use that farecla stuff. The da is way more aggressive,
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rusty nuts
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posted on 14/6/12 at 09:13 PM |
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I have an electric Einhall ? DA sander that I brought from Toolstation for peanuts to do just one job which has done loads in the last few years ,
ISTR it cost about £30 The only reason I brought it was I didn't have a decent compressor at home . Compared to a good air powered sander it is
OK
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owelly
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posted on 14/6/12 at 09:45 PM |
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I'm also bemused as to why your sander isn't taking the shine off. What abrasive paper are you using? Is it getting clogged-up?
http://www.ppcmag.co.uk
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blakep82
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posted on 14/6/12 at 09:56 PM |
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its not getting clogged up no, but then its no taking anything off. ok its the crap paper sample that came with it, so not the best, but its still a
120 grit paper. i'll try a bit of wet and dry paper in it and see what happens there
the gel coat is very hard, (i've never really paid attention to gel coats before, so don't know if there's different hardnesses?)
and the sander is very cheap. maybe the amount it moves (the radius of the vibration?) is very small? smaller than a proper quality sander? maaybe
most of the vibration goes through the handle? i don't know. I hate sanders, and sanding...
________________________
IVA manual link http://www.businesslink.gov.uk/bdotg/action/detail?type=RESOURCES&itemId=1081997083
don't write OT on a new thread title, you're creating the topic, everything you write is very much ON topic!
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mark chandler
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posted on 14/6/12 at 10:53 PM |
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I picked up a pretty decent DA from wickes, own brand think it was around £35
That said I am rubbing down mine to repaint and using 580 wet & dry on a very firm sponge, its taking a few hours but is giving me a much better
finish.
Just do one panel at a time, few hours on back panel, few on nose cone etc, sometimes power is not the best way. Use a spray bottle with water and a
couple of drips of fairy to lubricate as you go, a few rubs, rince clean and rub again.
Regards Mark
[Edited on 14/6/12 by mark chandler]
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owelly
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posted on 14/6/12 at 11:02 PM |
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I have a Black and Decker sander, the one that looks like a steam iron. The DA attachment will wallop through gelcoat with ease and you have to be
really careful on edges of stuff unless you want to be through to the CSM! The non-DA wibbling triangular base plate also munches through gelcoat and
I'm sure any machine that buzzes the pad about should be pretty similar. I've used a cheapo sander at work and it seems to do pretty much
the same job.
As you say, try a different paper. FWIW, I use the stuff from Screwfix.
http://www.ppcmag.co.uk
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twybrow
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posted on 14/6/12 at 11:18 PM |
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I too am baffles as to why you are having such issues sanding gelcoat. There is a chance the manufacturer of the part put
carborundum grit in it... It makes gelcoat/resin virtually
impossible to cut or sand.
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bartonp
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posted on 15/6/12 at 06:30 AM |
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I bought the Clarke DA electric from machine Mart for abou £25. Bloody marvellous, gets used on everything now (house, boat, car...).Even floorboards.
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Phil.J
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posted on 15/6/12 at 07:21 AM |
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I have tried a couple of DA sanders on my 3hp 14cfpm compressor and they hardly rotate. I can't get a rattle gun to work either. It's
because I piped it up with 10mm bore pipe and should have used a min imum of 13mm, the existing pipework simply can't deliver sufficient air
fast enough.
Having said that a working DA sander is the way to go if you have a large amount of area to cover, but if you are only flatting then working by hand
with water is probably best.
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plentywahalla
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posted on 15/6/12 at 07:43 AM |
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i wouldn't go for an air driven one. Air is best when the tool is used continuously and an electric equivalent will overheat. I have 2 DA
sanders, a Bosch and a Makita. They are used for hours on end and have never suffered from overheating as the vacuum pulls enough cooling air
through.
You would need a big compressor which will cost more to run as it is less efficient. Also air tools are much heavier and you will certainly notice the
difference. The Makita is lighter than the Bosch and I know which one I prefer after a few hours.
Your problem is almost certainly the qualty of the abrasive. What comes supplied with the tool will be the cheapest rubbish they could source. Buy 240
then 400 grit papers from 3M or Norton and they will cut through the gel easily.
Rules are for the guidance of wise men ... and the obedience of fools. (anon)
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