Question 1- If you have a hand saw I would use it to cut the required section. that way the edges will be much cleaner as for the curved section I would use a coping saw or something along those lines perhaps @MitchellMc can let you know what they have available in store.
Question 2 - the putty knife is to apply the filler after the new section is glued in place
Question 3 - Liquid nails is too thick and will not allow the packets to sit flush where the PVA allows for a bonded / flush finish. Ensure you remove any paint of the three packer strips other wise the glue will not work.. (you can turn the packers over and use the un painted side for the packers)
As for Question 4 I do not use that brand of tool hence unable to answer this question I will assume it is screwed in place???
I think using the sanding head with coarse paper (at first) on the multi tool would be safest for cleaning up those edges. Or a block of wood with sand paper as 23ron suggests. A chisel can cause much damage & gouging if used incorrectly. The attachments to the tool should not be coming loose under any circumstances. They fit with the small prongs on the tool going into the small holes in the attachment, so it all shakes together, then the screw down the centre is tightened firmly using the supplied key (aka "Allen key"). Put it in vertically (long end into screw head) to spin the screw down until it bites, then turn the key around so the long end sticks out to the side to give good leverage to tighten it firmly.
Here's a short video... note that the guy almost puts it on upside down at first, plse make sure that you are fitting yours correctly (it may look slightly different to yours).
If you have a hand saw use it to cut the new panel edges, if not, the semi circular saw on the multi tool can do it if you go carefully. First cut the outline with a knife blade, this will give a cleaner edge no matter what saw you use. Tape or clamp the template to the new panel , so any slips while cutting will only be on the bit you are discarding.
PS: don't be using the long bladed saw attachment with the multi tool for this type of cut. The semi circular blade gives a more stable direction for long straight runs. The thin, long one is best suited for "digging in", such as cutting out notches. I think I recommended that blade for removing the panel in my first post on this subject.)
This item is available in store but not for click n collect?
I did the sumilar thing but didn't remove it out fully as my attachments are not full ring just half....but will try removing the screw fully and attach the trianglur head to clean edges
I used the small straaight head yesterday
Also, I would like to confirm if removing all the honey comb or only where it is required(top, middle, and bottom)
It's great that you've been receiving fantastic advice from @r23on, @TedBear, and @MitchellMc. The 1220 x 915 x 3.2mm Masonite Whitecote is a large item and is not available as a click-and-collect. Let me reach out to you by private messaging so I can provide you with some assistance.
Hi @newfast , I recommend leaving as much of the honeycomb in as you can so it can help to prevent the inserted panel bending inwards. If you put some glue on the outer edges before finally inserting the panel it will hopefully stick to it and help prevent it flexing outwards too. The reason I originally suggested putting some wooden supports across the centre of the hole, not just the edges, was to stop the possible bending, but the honeycomb is in the door for that purpose. If you remove it, then I suggest that you include a thin timber strip across the hole centre & glue the panel to it, otherwise the panel could be used as a humidity indicator as it flexes in & out with weather changes.
Regarding the back panel break:- is it in the area of the hole you have made? If so, I suggest that you drill a small hole through the crack (it needs filling anyway) and through the internal panel, so you can see from the inside exactly where the damaged area is.
Then, from the front, carefully using the Multi-tool, cut a hole through that inner panel just big enough to put two fingers or a small bit of wood through. Then you can push the cracked area back out, to flatten it against something flat that you can hold up against the back. (Bit of wood or a thick book, etc). If you can find something to put through the hole in the inner panel to push and hold that break straight it would help you heaps. If you cut some strips from the new masonite the right size when turned sideways to sit between the inner panel and the back panel. (They will then act as the honeycomb does in the front, keeping the back panel straight. Cut the strips the size of the gap between inner andback panel. Open the hole a little if necessary to put them through. Put some glue on, wherever you have access, to stop them moving.)
There are so many small little tweeks one must know to get the job done...
Hats off to all who do this as a hobby
@TedBear , I haven't done much since otherday, been busy with work. So Honey comb is still intact ( 2nd pic)
Re drill a hole from open panel side (1st pic) based on measurements it is where I am pointing.
Also, the main item isn't available in the closest bunnings and delivery charges are kinda much more than the actual item.
Tomorrow I will try to use the triangular head to sand the edges but I have a hut feeling that the head will keep coming off...
Also...Will it be easy to adjust the glued strips in case I make mistake?
@newfast it's handy that the other crack is at a place where you can get at it by making a hole through the inner panel. Masonite is a common product... is there no other supplier near you? If you use the PVA glue it is easier to cut through with a knife if you make a mistake than Liquid Nails (thicker but stronger) and doesn't set quickly (thus the need to clamp it while it sets), so you can adjust things as you go. That head should not be coming off if fitted carefully. The damage to the holes in the photo you supplied suggests that the blade was not sitting onto the locating pips on the tool when it was tightened down. It may be safest to remove the anchoring screw completely and see that the head is sitting down on those lugs fully before putting the screw on. Tighten it down firmly and it won't come loose. (If it does the machine must be faulty.)
A tip: when you cut the new piece, cut it as a rectangle and do the curved corners with a Stanley Knife (or similar). Cut them by a shallow cut at first, then use that groove to giude the cut deeper, layer by layer until the cut is through.