Orbital or Random Orbital Sander

[davidpbo]

Orbital or Random Orbital Sander,

What is the difference please?
I have an orbital and small belt sander.

Also where do I get a coupler to attach to a vacuum cleaner please? Both pipes are the same diameter.

 

[John the kiwi]

coarse and fine maybe

I have a Hitachi random orbital sander as well as a 1/3 sheet finishing sander.
for some reason of physics random orbitals can sand with coarser pads without clogging faster and for longer. So the random orbital is really good for the brutal coarse sanding jobs like removing paint. I tend to use my finishing sander for, well finishing really. I like having both available.

 

[macd]

As above, plus a plain orbital sander inevitably is sanding across the grain on much of it's area. A random orbital motion much reduces this effect, leaving no 'pick up' effect.

 

[davidpbo]

Is there any appreciable difference between them when sanding fibreglass.
I have to sand a long bevel in the cabin to complete a repair and want to try and limit dust so dont really want to use an angle grinder and don't have an adaptor to fit a vacuum to my belt sander.

 

[boatbuilder]

We use masking tape to connect sander to vac, cheap and strong.

 

[macd]

Is there any appreciable difference between them when sanding fibreglass.

As John the Kiwi mentions, random orbitals are less prone to clogging than plain orbitals since each bit of abrasive 'attacks' the job from a different angle with every pass. But sanding grp, except simply to roughen the surface, ain't much fun. There may be a better way, if you can describe the job more fully.

 

[oldsaltoz]

When selecting an orbital sander look at the size or the orbits, a 3mm orbit will make short work of fibreglass but still be easy to control, you could be there for days with a finishing sander.

Good luck and fair winds.

 

[davidpbo]

As John the Kiwi mentions, random orbitals are less prone to clogging than plain orbitals since each bit of abrasive 'attacks' the job from a different angle with every pass. But sanding grp, except simply to roughen the surface, ain't much fun. There may be a better way, if you can describe the job more fully.

I am bevelling the edge of repair prior to reglassing.
See post 27.

I do have an angle grinder but feel that maybe a bit fierce.

 

[macd]

If I've got the scale right, I'd probably use a Dremel. Lots of dust but maybe possible to knock up an enclosure with builders' polythene to catch most of it?

 

[davidpbo]

Ended up using belt sander and detail sander for side 1. Angle grinder with disk flap wheel & detail sander for t'other. Probably belt sander with attached vacuum inside. Thanks all.

 

[Niander]

I had one it spun round but stopped spinning when using
it then was just like a normal vibrating sander...ive got them anyway
not what i wanted ...i got rid of it
do some spin under power?
thats what i would want

 

[nigelmercier]

I had one it spun round but stopped spinning when using it ...

You were pressing too hard.

 

[Amulet]

Orbital or Random Orbital Sander,

What is the difference please?
I have an orbital and small belt sander.

Also where do I get a coupler to attach to a vacuum cleaner please? Both pipes are the same diameter.

An orbital sander orbits - no surprise - maybe two to four mm. The detailed spec should tell you the size of the orbits. This can create swirl marks - little circles the size of the orbit where a particularly aggressive bit of grit has created a scratch. A random orbit sander rotates while it orbits, meaning that no particular bit of grit gets a chance to create a visible circle. At least I believe that's the theory, and it is consistent with my experience.

I have a few bits of vacuum connection hose and adaptors which I believe I got from aptc, which is a supplier all boat owners should know about - no connection to me, just a customer.

 

[Niander]

You were pressing too hard.

I was hardly pressing it was a **** powercraft type!
there must be some that are power spin!?

 

[dollopskiver]

Regarding attaching a hoover to sander, I had a the same problem finding an attachment to connect a DeWalt random orbital sander to my Henry vacuum cleaner. I spoke to my next door neighbour about this, he sells janatorial supplies and he found what I was looking for for about £5, incidentaly, the corrugated hose on that type of hoover is left hand threaded,ie you screw the fitting on the "wrong" way.He tells me that sections of corrugated hose can be bought to any length, I may do that yet so as to give me a bit more workroom under the boat.