Advice on scribing please

[DTR]

Evening all,

I regret to say that my long overdue built-in bookcase project started today, and predictably I've noticed a problem already.

The bookcases are going to stand in alcoves on either side of the chimney breast. I am going to fit a face frame that sits flush with the front of the chimney breast, then plant the skirting and coving onto the front. I was prepared to scribe the thin edge of the face frame where it meets the chimney breast reveal. Unfortunately, I've just discovered that the front face of the chimney breast is neither straight nor plumb. Of course, this means that a flat and straight face frame cannot possibly sit flush with the front of the chimney breast.

What is the best way of tackling this? Shall I plane down the thickness of the face frame in localised areas until it's in line with the wall?

I should add that the bookcase carcasses aren't built yet, so changes to the structure or positioning are still possible.

Thanks

 

[Bradshaw Joinery]

There are two ways Sit the bookcase the the furthest most point into the room on the chimney, then use a architrave type moulding that bridges the gap and caulk/scribe a fillet on the back edge that sits against the wall that s out. Or sit the bookcase back, and have just scribe in one direction, you will see the difference in levels this way more, unless you leave a decent distance from the corner.

 

[MickCheese]

Would you consider them sitting a little proud of the alcove?

If so I will try to describe how I did it recently.

I made the shelving and it was about 50mm proud of the alcove and I made them about 10mm smaller than the hole. I then made the face frame so it covered the gap and put a return back to the breast and just scribed the return. That way you only need to scribe in one dimension.

I got this from a post ages ago by Brad Nailer who no longer posts here but I will try to find it as he describes it better than I do.

Mick

 

[MickCheese]

https://www.ukworkshop.co.uk/forums/four-mdf-alcove-units-wip-t30678.html

There you go. Wow from 5 years ago, doesn't time fly.

Such a shame he doesn't come here any longer his techniques were really very good and I learnt a lot from his posts.

Mick

 

[Random Orbital Bob]

do you think Brad Nailer was his real name

 

[MickCheese]

do you think Brad Nailer was his real name

No, and I couldn't remember what his real name was.

Mick

 

[Random Orbital Bob]

sounds like a great name for an American movie star

 

[MickCheese]

Having looked back through that thread it seems it was Duncan, so not a movie star name at all!

Mick

 

[mailee]

It's Duncan Cheslett, and yes he did post some very good tips. He is still about...honest.

 

[glynster]

My favourite trick to scribe which is more accurate than compass is to poke a pencil through the middle of a small plastic lid - Pringles lid is ideal. Then run it down the length of your wall - unlike compasses you dont need to keep the angle of the compass square because your guide is round. Works a treat - scribe the last 3 inches with a compass set to the radius of the Pringle lid.

 

[Bluekingfisher]

My favourite trick to scribe which is more accurate than compass is to poke a pencil through the middle of a small plastic lid - Pringles lid is ideal. Then run it down the length of your wall - unlike compasses you dont need to keep the angle of the compass square because your guide is round. Works a treat - scribe the last 3 inches with a compass set to the radius of the Pringle lid.

That's a great tip, similar to which I have used in the past. The only issue with the plastic lid is the comparatively large radius of the lid which can be problematic when the amount needing removed is small or the gap requiring scribed is small.

In the past I have used a small pencil found in the spines of pocket diaries poked through an M5 washer. Of course any washer depending on the gap would suffice. A layer or two of painters tape around the pencil takes up any slack in the difference between the hole in the washer and the pencil.

The principle is the same and removes most of the error common on compass and pencil technique and you can scribe right down to the base.

David

 

[DTR]

Thanks for the replies so far.

Just realised, I didn't make it clear that we are trying to avoid any kinks or joints in the skirting and coving. Hence why the scribing is a problem. One idea is to set the bookcases + face frame back into the alcove by an inch or so. Then plant a fillet onto the front of the face frame to bridge between the face frame and skirting / coving. The fillet can be moulded etc on the visible edge. The fillets can be slightly different thicknesses (within reason) to allow of the walls being out of plumb. How does that sound? I think this is very similar to what Bradshaw Joinery posted above, but in a different plane, unless I'm reading that wrong?

Failing that, I think the preferred option is to give up and set the bookcases back as far as possible, then run the skirting / coving back a short distance along the reveals.

 

[DTR]

Oh, and Brad Nailer is an awesome name =D>

 

[wcndave]

Reading all the replies and ideas, I am finding it very difficult to visualise this. I am about to embark on some built in furniture, so would be interested if you have any other resources on what all this filleting etc is? Thanks.

 

[RobinBHM]

If you want the room skirting and cornice to run straight without any mitre returns, I would as you are suggesting, set the face frame back from the plaster return.

Then fit a packer to fill the gap between the back of the skirting and the face of the front frame. A thin scribe, say 30mm x 6mm can be used up the sides, butting between skirting and cornice. Keeping it thin means it wont sit proud of the flat part of the skirting moulding.

If you make your face frame so the inside edge is higher than the skirting by 30mm or so (and lower than cornice by same amount), then you wont notice if the skirting / cornice doesnt run parallel to the face frame.

I usually make the top and bottom of the face frame 80 or 100mm wide, allowing for skirting fixing.

 

[DTR]

Having discussed it some more with SWMBO, we are now thinking of ditching the "flush" idea altogether and setting the bookcases back. The skirting and coving will return back to the face frame to wrap around the chimney breast. We think that this will look better.

Your tips have not been in vain though! I've learnt a few things that will come in handy for my future projects. Thanks everyone!