Needing to find same router bits

[opps]

Except for the edges, which can be a problem to seal. I'm sure @opps can advise better than me about this. If using MDF to take a profile it is better to use MR-MDF because any profiles machined in it are far less woolly. TBH red deal will give a crisper profile than MDF

Agreed, moisture resistant MDF will have far less "punky"/furry edges. The increased level of resins results in much harder edges.

Years ago, when I worked for a cabinet maker, we used to brush on a Morrells high build MDF sealer on routed/profiled edges, it was a two part sealer. The stuff was very, very hard. We (read: I) would spend hours sanding it flat using wire wool. It made the routered edges (almost) as tough as the rest of the MDF.

I don't think they make it any more but they do have a pre-catalyst version.

Morrells 329 High Build Pre-Catalyst MDF Sealer - Wood Finishes Direct

Morrells 329 High Build Pre-Catalyst MDF Sealer is a quick drying, 32% solids pre-catalyst sealer formulated for use on all substrates, especially MDF.

www.wood-finishes-direct.com

Unfortunately, it is only available in 5L and costs about £45.

These days, I tend to (heavilly) brush on about 3 coats of Leyland Trade acrylic primer and sand back the paint build up with 180g silicone carbide paper. I use Leyland because it is one of the few acrylic primers that doesn't clog my abrasives. Silicone carbide paper is far more flexible than aluminium oxide paper. I sand until I have pretty much removed most of the paint.

Although not the edge of the MDF, the following image shows how much of the primer I sand away.



(As per the above image, it is a myth that MDF is perfectly flat- it has score marks in it from the manufacturing process. I guess the sheets run through a massive drum sander. Waterbased primer will raise the "grain" which I don't see as a problem, given that I am going to sand it flatter than when the MDF was manufactured.)

The finish (sanded edge) is absolutely fine for hand painted finishes. If spraying with 2K paints I normally hit the profiled sections with two coats and then sand flat with 220 grit Abranet.

I have seen other people recommending Zinsser BIN for the edges, but it is pig to sand. Owatrol oil will also work, but dries very slowly (and is more expensive).

To be honest, the edges are less knock resistant than the likes of Morrell but if knock resistance is paramount, you shouldn't be using MDF.

BTW, the likes of ISF also make similar products

ISF Hi Solids MDF Edge Sealer Clear 5L

Low Price GBP 10.5 5L Pct Standard Thinners

tools-paint.com

 

[2020c]

the angle will be half at around 22.5 compared to 45% and you wont have an around 4x8mm step so quite a visual difference that may be reduced by a bit off around 4x8mm planted on ??

Yes I agree but it's the best I've seemed to have found thsts not very expensive.

 

[big-all]

Yes I agree but it's the best I've seemed to have found thsts not very expensive.

indeed i suspect it needs a paired cutter set as repositioning doesnt work for the reverse profile ----- i think

 

[2020c]

indeed i suspect it needs a paired cutter set as repositioning doesnt work for the reverse profile ----- i think

For all thst I need it for I'm sure I'll manage it. It's just it is different from my own doors and wouldn't want it to noticable as mentioned above.

 

[2020c]

No going back now. Will update with pics of the doors made just for reference for others. Hope I don't make a balls if it lol

 

[Notch7]

my tips:

if you want to replicate the look of painted oak, I would recommend oak veneered mdf rather than birch plywood -although you may be restricted by the groove of the cutter set

if you use birch ply, it comes in varying grades, the better grades have less knot cutouts -usually an oval shape -you can have those on the face side

personally I think you might struggle with softwood -I would choose moisture resistant mdf, ideally Finsa hydrofugo mdf. Sand the mdf moulding before assembly. work through the grits from 120g to 320g -if you sand it hard it will burnish the edge and will absorb less paint

planed softwood from a merchant wont be very flat and will be prone to movement -you risk getting twisted doors

when clamping these doors together make sure the stiles dont tilt as pressure is applied -check the door flor flatness

make sure you clamp up with the door flat and when leaving to dry ensure they remain flat -if twisted your door will be twisted

 

[big-all]

make sure you have a sacrificial bit off wood when routing the end/cross grain as you will get break out

 

[2020c]

my tips:

if you want to replicate the look of painted oak, I would recommend oak veneered mdf rather than birch plywood -although you may be restricted by the groove of the cutter set

if you use birch ply, it comes in varying grades, the better grades have less knot cutouts -usually an oval shape -you can have those on the face side

personally I think you might struggle with softwood -I would choose moisture resistant mdf, ideally Finsa hydrofugo mdf. Sand the mdf moulding before assembly. work through the grits from 120g to 320g -if you sand it hard it will burnish the edge and will absorb less paint

planed softwood from a merchant wont be very flat and will be prone to movement -you risk getting twisted doors

when clamping these doors together make sure the stiles dont tilt as pressure is applied -check the door flor flatness

make sure you clamp up with the door flat and when leaving to dry ensure they remain flat -if twisted your door will be twisted

Ty I will..thanks for the advice.

My doors have a small curve on all corners. Is this done by router or do I sand them to take the squareness out of them

 

[big-all]

not sure what you mean by "curve on the corner" but iff its the corner as on a postage stamp[flat surface ] but not away from the back then router fully and join as you cant curve mated faces so any rounding will be post assembly and gluing

 

[2020c]

not sure what you mean by "curve on the corner" but iff its the corner as on a postage stamp[flat surface ] but not away from the back then router fully and join as you cant curve mated faces so any rounding will be post assembly and gluing

The corner of the doors. It's like they've been routered or sanded on the edge of them.

 

[big-all]

ahh right ---roundover as in radius edge--i think perhaps 6mm radius

as an asdide when i went back after typing 5 mins later i got a different image in my head so perhaps an image with an actual corner in it to give scale and definition

 

[Deleted member 174758]

Radius edges are easier to get a good finish, especially when spray finishing. The radius is often just 1 to 2mm, not 6mm. Basically, you can achieve the same result by simply hand sanding the edges with the paper held in the hand