Worksurface jointing

Discussion in 'Kitchen Fitters' Talk' started by ajohn, Nov 10, 2018.

  1. ajohn

    ajohn Active Member

    I've had a suitable router for a long time ;) but used the kitchen to justify buying an upgrade. Have also bought the usual jig. They claim it can cope with more angle error than others but info on how is entirely missing. All instructions seem to rely on adjacent walls being reasonably square to each other. Only one video I'm aware of mentions how to set the jig correctly for some width of worksurface and also pulling off the wall etc leaving a gap to correct for wall errors. Setting the jig is good info as there may not be a peg hole for the width some one has and the peg may not be good enough on it's own anyway.

    What's worrying me is that I wont really be sure about how square the walls are until I actually come to do the job of fitting them in a U, 2 sides about 2m+ and one somewhat shorter. Splash back tiles allow up to a 6mm gap absolute max and 5 really. It wouldn't take much of an error in the angle of the walls to eat that up. One wall I know has about a 5mm bow in it. That run has a free standing cooker in it but if the worksurface past that is pushed against the remaining wall it's unlikely to be square to the next wall or maybe it will be. No way of knowing. I can scribe the back of the last section pretty easily - no units under it, ;) Just a built in dog cage so a straight saw cut along the back should do it.

    Is there anyway of using these jigs that a can account for errors in the angle of the wall or any other tried and tested method of jointing that can? It seems to me that the main aim with the usual jig is to obtain mating angles on the 2 pieces that are being joined and these needn't be at 90 with a short 45 degree section - the joined lengths just need to be the same. :( Can't see how this can be done though and this aspect seems to be glossed over on every instructional video I have seen.

  2. sospan

    sospan Well-Known Member

    just covered why pros get paid to fit kitchens ;)
    RolandK, kitfit1 and Jord86 like this.
  3. Jord86

    Jord86 Well-Known Member

    A 4ft folding Stanley square, 6ft straight edge and simple old 3,4,5 rule will tell you how square and flat you're walls are.
  4. kitfit1

    kitfit1 Well-Known Member

    They really tell you nothing about how accurate you might be Jord86.
    The way to do anything with worktops is to fit the base units first. Then just use a long length of plinth to sort any angles out. To be honest even that is a waste of time. Get the first top in, measure the overhang from the corner, add 3mm and then cut the male joint....................follow that all the way round. Jobby jobbed and perfect joints.
  5. sospan

    sospan Well-Known Member

    Your both coming at it from different angles ;)

    Jord is talking about the walls, Kit is talking about fitting the tops
  6. kitfit1

    kitfit1 Well-Known Member

    The most important thing though is actually fitting the tops.............................not some mathematical way of working it out :D
  7. ajohn

    ajohn Active Member

    There is one video that goes through it properly. This one ;) anyone that can set the depths of a router in 1/2" steps like that without thinking about it must do a lot of them. A rather long video though.

    Like most he cuts females first and then marks out the male and transfers the lines to the other side so that they can be turned over and routed without chipping the covering. Why do males first. Does it offer some advantage?

    On the female part he does the end wall is reasonably square to the other one - no bulging out in corners - something plasterers sometimes leave. Pain but easy if it's a problem scribe to fit first.

    When he does the male and uses a the female joint to mark out he has both pieces pressed on their walls. That makes sure that the long straight section on the joints will line up correctly. It doesn't make sure that the short 45 degree length and the curves will line up as the jigs assume that the joint will be used on work surfaces that are at 90 degrees. It's the little sections on the end not matching perfectly that is bugging me and if there is another way of using the jigs to make sure they do if adjacent walls are too far out of square.

    I'd agree about 3 4 5 triangles - lovely idea that can be used for some things but it doesn't 'arf have to be done accurately to actually measure angles. It would be better as suggested to use the work surfaces as they have more length and measure the angle they are actually at. In my case that could be done with lengths not far off the length they will be when fitted. ;) Not sure if doing this will help use the jigs though.

  8. Jord86

    Jord86 Well-Known Member

    Amongst other things, I was also being facetious, expecting a kind gentleman such as yourself along to offer his two penneth. Which now you have. Also, as much of a joke as the mathematical phenomenon 3 4 5 may seem to some, it's still a certainty to check for square, along with the 4ft Stanley and straightedge I mentioned. Especially to a DIYER. As you are a trained cabinetmaker, I would think before you fitted a kitchen into an empty space these would be preliminaries you would check.

    Believe it or not, mere mortals are capable of fitting kitchens to a Godlike standard too..........
  9. Scott Green

    Scott Green Member

    When i drop a worktop into the corner, if i can see it isn't square, i would adjust the female cut a fraction to accommodate. Take a bit more out or a little less on the angle rather than just going to the pins. Then drop the next top on top, mark underneath and bobs your uncle.
    Probably easy to say when you do it all the time, but don't overthink it
  10. ajohn

    ajohn Active Member

    ;) Don't over think seems to be a good idea. It's just an obvious problem I guessed that things needed to be frigged a bit to get round it. The problem is simple really. The jig assumes 90 degrees so say one side is cut straight from the jig and the other is done via marking out with it that results in the jig being used at some angle other than 90 degrees. The joint length on that piece will be longer as a result so can't match up exactly. The question is really how exact it needs to be. What it might mean in the case of the video is that the female part might need pulling back a bit to get the 45 degree angles to match. ;) Great if it turns out to be as simple as that but walls vary. The end of the female part might need scribing to get it to fit well across it's width anyway.

    I can see that there isn't much scope for seeing what is needed until some worktop has been laid on top of the units. Take my ideal 5mm max gap between the back of the worksurface and the wall. Works out that would need the wall to be within 0.14 degrees over 2m if it's straight. Measuring to that level just isn't on.

    :) I have had to do some scribing already. How I did that might interest other DIYers. I don't know what a pro would do. As the old sink had to go I have finished the end of the kitchen where it now is. I'd left an alcove for it when a wall was removed. The stub wall left was plasterboarded deliberately thickening away from the main wall on both sides so that units can be angled a bit if needed and fitted directly onto it. The other side of the alcove is formed by a new wall - laid out with a 3 4 5 triangle as the builder wouldn't have been able to measure off another wall. I know from tiling it runs out a good 10 to 15mm despite all the care I took. Pipework is boxed in onto the back wall un a corner just to make it more interesting. I made some templates for each end of the worksurface out of some 6mm stuff we had lying about and joined them with a strip of timber - that was used to align it with the worksurface when I routed around the template. Other than the boxed in pipe making the templates is easy. Just position and hold a pencil vertically on the wall and run it around the template - then shape it. When it fits add the length of timber etc used to align it. The end with the boxed in pipes needed a couple of goes - I used a file to finally get that right by eye.

    ;) Nearly had a nasty shock when I came to lower it in place at an angle. I'd scarcely left enough clearance. Probably because I was trained as a toolmaker so may be inclined to work more accurately than I need to at times. It wouldn't have been a problem though - just reposition the template slightly and reroute one end. Despite the extra work it didn't take long to do. I'd already bought a cutter with both top and bottom guide bearings thinking it would probably be useful.

    One thing I found on the way was that my jig saw works well with ordinary blades - load of **** with down cutting ones so I routed the hole for the sink out as well by setting up straight edges to use a guide.

    Been interesting work so far. Preparation of the room has taken a long time. More plumbing changes needed than expected and not easy to do. Erecting and fitting units doesn't take long. Worksurfaces shouldn't either. Main problem is old house and previous modifications and remedial work to try and keep the fitting easy - even feasible in some cases.

  11. Gavo 78

    Gavo 78 New Member

    As Scott says

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