Pro shop MDF edge sanding.

[hansonread]

Just wondering on forum users methods for preparing MDF edges for painting.

I currently use a celulose based sealer, which I spray apply, then hit it with the RO, with very good results, however not the quickest of ways. Does anyone use an edgsander? worth the 6k price tag?

 

[nathandavies]

MR MDF, mirka ROS no sealer, once in the flow it's quite quick,
wouldn't mind hearing how good an edgesander is though.

Nathan

 

[Silas Gull]

I have used : shellac, drywall compound, acrylic gesso, varnish, but the thing that works best for me is plain old pva.
The drywall gives a very flat finish initially but because the mdf sucks the life out of it, I found it to be fragile and prone to cracking. It laps up shellac like a wino on speed, ditto varnish. The gesso is encouraging but hard to smooth during initially application.
I guess a lot depends on the quality of the mdf.

 

[rileytoolworks]

360, 600, 1000 then 2000 grade abralon pads.
Really quick, and polishes the MDF.
One coat of primer, denibbed comes out like glass.

Adam.

 

[hansonread]

Yeh I only bother with MR KRONO now, that certainly does make a huge difference, wish they made it in sizes above 35mm though :/

I use Morrells MDF sealer and this stuff is absolutely wonderful, I will quite happily send some samples out of this stuff just so other people can go wow at it, its speed of drying is what does it for me but I cant sing its praises enough.

I then hit it with 180g Abranet on a 125mm 5mm orbit Mirka Ceros, this makes it very smooth, with only slight pitting, which normally the primer in the next stage fills nicely, if anything is shining through like a sore thumb after denibbing with 320 or its being finished in anything over 70% sheen then I then apply a clear grain filler, to affected area or the whole panel if being finished in high gloss. and hit again with a 400g Abranet on a 150mm 2.5mm Mirka Ceros sander.

The system I am quite happy with, just wanting to see if I could speed the sanding element up a bit, as even on an average job, there are hundreds of meters of edges to sand.

Hence why I was asking about a edge sander? Anybody have one?

 

[mailee]

120 grit, brush on one coat of zinnser bin, 320 grit, prime, 600 grit top coat. high gloss a couple more coats of primer, jobs a good un.

 

[Chrispy]

I don't know what you're looking for at 6k but I have a old Danckart edge linisher about £150 at auction, this is what I use for anything that I can get on it and it's fantastic for fitting doors etc fitted with g120 or 150 leaves a surface ready for the MDF sealer.

 

[hansonread]

http://www.ukfelder.co.uk/gb-en/product ... 00-kf.html

or anyone tried one of these?

http://gibbsfinishing.com/gibbs/mdfedgesanding.shtml

 

[tezza111]

Much much easier just to edge band it all in white paint grade edge banding. Its a very simple process with an iron and a sharp stanley blade and a little bit of practice and leaves a white paintable smooth finish. Saves all that sanding and sealing.

T

 

[Graham Orm]

360, 600, 100 then 200 grade abralon pads.
Really quick, and polishes the MDF.
One coat of primer, denibbed comes out like glass.

Adam.

As I'm in the middle of doing a couple of radiator cabinets and just at the point of applying finish I have been pondering on this. I was going to try car filler, but thanks to rileytoolworks all I need is some elbow grease.

just been out to the shop to give it a go, see below....sorted! down half a dozen grits finishing with 2000. No filler required!

BEFORE

AFTER

 

[hansonread]

Yeh I have tried that paint grade edge banding, found it to be slower in the long run compared to sanding sealing on bigger jobs. For example, last job I processed had 560m of edging to apply, so I wouldn't fancy ironing that lot on! and haven't found a non glued version I could put through my edgbander as it has a glue pot.

I cant fault it for smaller jobs, or one off's though.

 

[custard]

It's interesting, once your eye is attuned to the problems of dealing with MDF edges any ripple or roughness leaps out at you. But when you point it out to the general person in the street they're almost oblivious to what, I would regard as, sloppy work. The typical reaction is "nothing wrong with that" or "I wouldn't bother about that", and this from people that are pretty fussy!

Consequently for my personal work I go to extreme lengths to deal with MDF edges, applying poplar lippings at the drop of a hat because anything less would distress me greatly! But for commercial work I check to ensure the customer really wants and is prepared to pay for multi stage preparation, otherwise it's a coat of Zinsser Bin and on with the paint!

 

[Tom MasterCraftsman]

I've been spraying mdf for years as a cabernet maker, there is no need to waste time edging or sealing, just get a good random orbital sander with 120 grit or 150 if you prefer, then using a good primer paint applying more to edges than the flat surfaces, then rub down with a suitable 240 grit paper leaving a good smooth edge to top coat,
You may need to prime twice depending on how good your primer is,

Although a good quality mdf a sharp saw and a good quality paint helps, it may cost a little more but will save time and produce a better finish at half the labour,

I've had the argument with many a decorator in the past about sealing edges on mdf, as always with finishing the quality is in the prep work not just applying the finish so a good de nib between coats is worth the time spent, many decorators only give a light rub but to achieve a quality finish you need to flatten the surface as well as denibbing but only experience teaches you not to rub to far.

I hope that helps, sorry if im ranting

 

[Graham Orm]

I've been spraying mdf for years as a cabernet maker, there is no need to waste time edging or sealing, just get a good random orbital sander with 120 grit or 150 if you prefer, then using a good primer paint applying more to edges than the flat surfaces, then rub down with a suitable 240 grit paper leaving a good smooth edge to top coat,
You may need to prime twice depending on how good your primer is,

Although a good quality mdf a sharp saw and a good quality paint helps, it may cost a little more but will save time and produce a better finish at half the labour,

I've had the argument with many a decorator in the past about sealing edges on mdf, as always with finishing the quality is in the prep work not just applying the finish so a good de nib between coats is worth the time spent, many decorators only give a light rub but to achieve a quality finish you need to flatten the surface as well as denibbing but only experience teaches you not to rub to far.

I hope that helps, sorry if im ranting

Not a rant Tom, excellent advice that I will be trying out very soon. Have a look at my pictures further up the thread, I had no idea you could get anything like that result on MDF.

 

[Tom MasterCraftsman]

Edge sanders can be effective and fast for production work, I've used a old one prob a wadkin or summit like that it was like a surfacer with adjustable in and out feed fences but the fences are vertical so you run your work flat, between the fences was a adjustable plattern which the belt ran on as well as two rollers, the entire belt and roller assembly also moved up and down so you used all the belt, you also had a table and fence on the other side of machine so you could use like a standard belt sander if brave enough,
Id recommended one if you did alot of edge sanding very fast leaving a super smooth edge, you can also sand things like table legs very quickly.

 

[vally bar]

Yeh I have tried that paint grade edge banding, found it to be slower in the long run compared to sanding sealing on bigger jobs. For example, last job I processed had 560m of edging to apply, so I wouldn't fancy ironing that lot on! and haven't found a non glued version I could put through my edgbander as it has a glue pot.

I cant fault it for smaller jobs, or one off's though.

Just put pre glued through your hot melt we do if we can't get plain.

 

[Bradshaw Joinery]

The Gibbs sandtech machines are quite interesting, it uses a weird rubber/plastic wheel that almost closes the edge of the mdf off with friction, you could paint straight on it, then de-nib, but i think there quite a fussy machine, and need a lot of setting up to get the speeds right.

I just sand with ROS, 150g then spray with good quality MDF paint. Sayerlack/morrels etc. Spraying with air assisted airless means a thicker coat on end grain/panel as its unthinned, so you only need a light de-nib and its fine. Dont want it taking too long to dry either, nice hot, dry room. If your really pervy, Tricoya is THE best mdf to use.

 

[hansonread]

Yeh i could do but we use PUR not EVA in our bander so there's a glue compatibility issue with using pre glued.

I cant tell you how much better things are since switching over to AAA instead of conventional when it comes to spraying, although, I still prime using conventional system as have large pressure pot set up with 30L of primer ready to rock all the time.

Im just curious with these grinder type sealer machines. Does anyone have one I can come and have a play with?

 

[Bradshaw Joinery]

i spoke to the guy for a while at the NEC, He was really helpful, im sure they would demo for you, or point you in the direction of someone that has one!

 

[RobinBHM]

Sorry to drag up an old old thread….but does anybody have or use the Gibbs edge sanding machine.

ive been offered one at a good price and I’m wondering whether that or an edge gander is the best solution.