Making Arched Doorframe for Door

[Augustus]

I'm fitting a nice old wooden external door with a gothic arch onto the side of my garage.

Not really sure how to approach the arched part of the door frame. What I have in mind is a couple of soild timber uprights and affix the arch to the top of these. I was thinking get a thick piece of timber from a local sawmill, make a template of the arch from the door and scribe this onto the wood, take it to a local joiner and get him to cut it out for me. and then fix it into position

This is completely off the top of my head - is there a simpler way of approaching this or are there any poten tial issues with my approach?

 

[blup]

Even for a flat arch you would need very thick piece of timber. The alternative is to make it in sections and glue/dowel together. Depending on how important appearance is, you could make an mdf former, and clamp bend and glue thin layers of suitable plywood over it (with a powdered resin wood glue like cascamite which will not move) The exterior (vertical) face could be treated with a veneer of oak or similar.

Blup

 

[big-all]

also keep in mind the arch off the frame needs to be around 15mm smaller radius so when rebated 18mm you have an all round 3mm gap and a 15mm overlap

 

[Augustus]

Even for a flat arch you would need very thick piece of timber. The alternative is to make it in sections and glue/dowel together. Depending on how important appearance is, you could make an mdf former, and clamp bend and glue thin layers of suitable plywood over it (with a powdered resin wood glue like cascamite which will not move) The exterior (vertical) face could be treated with a veneer of oak or similar.

Blup

Sounds a good approach - just wondering if this is going to be suitable for external used though - juat thinking all those bits of ply are going to swell and warp if they get wet unless I can thoroughly weatherproof it.

 

[big-all]

the simplest way to think off it
take 2 x50p coins lay on top and rotate the top one half a segment
now replace with say 44mm x119mm planed timber to give the same effect

 

[blup]

Sounds a good approach - just wondering if this is going to be suitable for external used though - juat thinking all those bits of ply are going to swell and warp if they get wet unless I can thoroughly weatherproof it.

If the ply is external grade and treated/painted it should be covered/ protected from the elements by the fascia and brickwork. There are some very good external heads hybrids polymer sealants to prevent ingress of moisture

Blup

 

[JohnD]

A simpler way would be to use a rectangular frame, and make curved infill panels for the top corners.

 

[Augustus]

If the ply is external grade and treated/painted it should be covered/ protected from the elements by the fascia and brickwork. There are some very good external heads hybrids polymer sealants to prevent ingress of moisture

Blup

It's not really going to be that well protected - it is barely under the eaves of the garage roof. The door in the pic is the one I'm swapping out with the arched door

 

[JohnD]

Set it in a bit.

 

[Augustus]

Set it in a bit.

Yep, can do that and keep it out of the worst of the rain but just need to make sure it's protected from the all pervading dampness that I get in this part of the world. Will look at the sealants mentioned by the poster above.

 

[martygturner]

Just kerf it , glue the slots and bend it round a dowel jig...

I used this site to get the cut spacing for a tree seat ring. https://www.blocklayer.com/kerf-spacingeng its in inches...

 

[Harry Bloomfield]

Yep, can do that and keep it out of the worst of the rain but just need to make sure it's protected from the all pervading dampness that I get in this part of the world. Will look at the sealants mentioned by the poster above.

The Cascamite is a waterproof glue.

 

[Augustus]

Just kerf it , glue the slots and bend it round a dowel jig...

I used this site to get the cut spacing for a tree seat ring. https://www.blocklayer.com/kerf-spacingeng its in inches...

Useful site - just can't work out what a sweep angle is?

 

[martygturner]

Useful site - just can't work out what a sweep angle is?

its the amount of a circle you want to make so 90 degrees is 1/4 of a circle