How would I neatly cut this old chipboard in place?

[frumbert]

I'm in an old house with a chipboard kitchen and no money to spend on a new one. While i've replaced most of the crumbly cupboards lower down, we have this custom wall cupboard which is fine for now - it just needs to be a different shape.

I want to cut out the chipboard about where you see the plates sitting so that this cupboard is tall, and then put a side in and a door on (clearly there's already been a door at some point in the past). I'll then seal and paint the interior, maybe add some lights in the top, and do something about that horrible bumpy liner stuff (that's a future me problem).

This shelf is already above head height, and its in a low ceiling area (2100) so it's an awkward area to work in - I'll likely be cutting from underneath. I'd like the cut to be as straight as I can get it so that when I add a dividing wall to the right I can reattach the remaining shelf to it to keep it solid. What tools or techniques would be best?

[MitchellMc]

Welcome to the Bunnings Workshop community @frumbert. It's wonderful to have you join us, and many thanks for your question about cutting a shelf.

Given your tight working conditions and the nature of the chipboard, there are a couple of ways you can approach this that balance neatness with practicality.

If you can elevate yourself safely, such as on a sturdy step stool or platform, and get above the shelf, using a jigsaw is likely your best option for a clean, straight cut. You’d want to mark your line clearly, then place the jigsaw flat on the surface and push it carefully towards the rear wall. Because you’ll be working close to the back, where access is limited, you may still need to finish off the final bit of the cut with a hand saw or even a flush cut saw if it gets tight. Keep in mind that chipboard can tear out easily, so using a fine-tooth blade and going slowly will help minimise chipping along the cut edge.

If working from the top just isn’t physically possible, then your best bet is to cut from underneath using a handsaw. In that case, clamp or screw a straight batten of timber along your cut line to act as a guide. This will help keep your cut reasonably straight and give you a cleaner edge to fix your vertical divider to later. It’s definitely more awkward and will be slower going, but it’s manageable with patience. Expect a bit of fiddling right up against the rear wall — you may need to nibble away at it with the saw.

Regardless of the method, it’s a good idea to seal the raw chipboard edges after cutting to prevent moisture from getting in later. Something like a timber sealer or even a coat of PVA glue will do the trick before you go on to paint.

Let me know if you want tips on installing the side panel and door once you’ve made the cut — happy to help with that next step too.

I'll tag @Nailbag, @Dave-1 and @AlanM52 for their thoughts.

Please let me know if you have any questions.

Mitchell
 

[Dave-1]

Good Afternoon @frumbert 

I have a kitchen just like yours And yep I have been thinking about replacing it by $$$$$ and timing come into play. I have just redone my foyer (almost ready to post the project) But here is a sneak preview...

Before, Particle board all overthe place but still nice.

With no ripping out, placing timber top on top of the existing particle board and overhanging it slightly, plus timber trim on the front of the shelves really brought the foyer up to spec.

Really just an idea on how you could go, I am thinking of upgrading my kitchen that way as well  

As to cutting the particle board Id screw a temporary timber strip across on the right between the two supports for the shelf and use a hand saw Bahco 550mm Hardpoint Hand Saw  while standing bellow the shelf. When it gets towards the wall, I would switch out and continue with a copping saw Trojan 165mm Coping Saw (Note you may have to do two cuts to get the copping saw in as the handle will be thicker then a blade cut by the handsaw) You could etech the line first using the handsaw by short horizontal strokes across the top of the shelf then gradually tilt the saw so the teeth start biting, make sure you etch the line first as it wake the job easier.

Dave

[frumbert]

Hmm, doing an etch line on the top would be a good idea. I think I'd have to temporarily take out that vertical timber somehow, it's kind of fiddly at the top and might be a little biscuit join just to be difficult. I'd wanted my dividing wall to be behind the vertical timber, it would simplify everything if I just cut beside what is already there .. but that wouldn't look as good! My old hand saw is a bit of a dud so might have to invest there, but I do have a coping saw and didn't even think of using it. I've used the jigsaw on old particle board in the past, and even with fine blades and going slow it makes a mess, I think I'll stick with hand tools. Your reno looks great - love the timber strip facing boards.

[AlanM52]

From underneath butt a straight edge against those two frame timbers and pencil a cutting line.

Do the same at the top to help guide the saw.

Use something like a Trojan 300mm Laminate Saw (0191074).

Start with a shallow cut (we need to get past that support) keep going to the handle.

Insert the nose of the saw into the cut on the other side of the support and finish the cutting.

If needed flip the saw over to get going.

I suspect the shelf is simply nailed but if screwed no matter.

Make another 5 or 6 cuts to the back and carefully pry off the sections.

You will need another board/shelf to do the side.

Cheers

[Dave-1]

Afternoon @frumbert 

Not sure if we are talking about the same place to cut so i drew it up

So the green highlighted bits on the shelf is where the new temporary pice is screwed in as a guide. This could actually stay permanant if you wished to give strength to the cupboard after cutting the middle shelf.

The round circled piece is a 75mm by 35mm piece of timber and screwed through the shelf from the under side. You could also screw through from the front vertical.

The pink saw is the line I am suggesting to etch with teh blade for a bit (1mm in depth say) and then tilt the saw so handle goes down and the blad goes up. The guide will keep you against that block and the angle will allow for a better and easier cut. If you want a really fine cut you could also use a hacksaw as there are more teeth to the inch. Tho the handle may want to make your cut stray.

And thank you for the thanks

Dave