UKH

gap beween two new kitchen worktops is about 1.5mm, worktops are about 2 metres long. i used a wood filler previously (https://bond-it.co.uk/mate-range/lami-mate-timber-sealant/) which lasted a few months but has now cracked leaving gaps for food/water to get in.

i did try and use a syringe to squirt the filler in deeper into the gap but it was too thick to go through the narrow needle.

any suggestions for filling the gap? cheers in advance for any tips!

Something like this perhaps? 

https://www.screwfix.com/p/goodhome-butt-joint-aluminium-40mm/832fy

Hard to say without knowing the type of worktop you have, but mixing a decent wood glue with sawdust could work. Bit of a bad time of year to do it, as the worktop may shrink slightly in the warmer weather and lead to cracks again.

Alternatively, some form of T trim should work. https://www.screwfix.com/p/goodhome-corner-joint-aluminium-29mm/388FY?tc=NT...

I.5mm is the worlds most tricky gap to fill. It's too small to get any filler down into properly and if the worktop shrinks by even half a millimetre, then the gap increases by 33% which is beyond what most flexible fillers can accommodate.

Either cover it with a aluminium strip (bodge) or remove one worksurface, clean the joint and stick it back together with epoxy so it's absolutely rigid. Any movement should then work itself out in the other direction.

Any scope to retro fit clamping bolts from below?

https://www.locksonline.com/Worktop-Connecting-Bolts-Two-Wings-One-Bolt-116...

As marsbar says, the standard way is with an aluminium butt joint. I've got one on my kitchen worktops and it works 100% fine.

That's pretty old school now. You wont see those on a modern posh kitchen.

How have you managed to get a gap between 'new' worktops?  Were they not 'butterfly bolted' together?

If OP doesn't want to rip* worksurfaces off the wall or whatever by pulling them together 1.5mm you could add lock nuts to rigidly hold the gap at 1.5mm and then use flexible filler.

*would that really happen?

Can you lift one up and biscuit join them?

OK, so there must have been some step forward using filler.

Variations on this technique...

youtube.com/watch?v=Ux3EZhhYdZo&

That looks superb, but requiring quite a lot of sophisticated gear. I suppose to do the job properly, you'd replace one of the pieces of worktop with a new, slightly longer piece so that you have some surplus material to work with, and then do it exactly as in that video, with those metal clamps and biscuit joints.

Wood slivers (normally used for filling gaps in floorboards) might work. They have a wedge shaped cross section, so you can tap them into the gap for a tight fit:

https://www.finwood.uk/wooden-floor-finish/pine-slivers-gap-filing-floor-bo...

This...or marine decking caulk

I find a good agglomeration of breadcrumbs, butter residue, dead skin, dust and fatty deposits seal up the gaps in my wooden kitchen worktop just dandy.

regularly topped off with bees-wax and tung oil obviously

If the boards aren't tied tightly together at the joint whatever you put in there will probably open up again come summer. If they are tied together, clean the joint, tighten the nuts then go figure out what broke at the other end to give you the movement.

Assuming you don't want to get under there with a router I'd screw some metal plates to the underside to maintain the gap then fill the joint with a coloured silicone

jk

Can you fill the gap with thin cork sheet to just below the surface and then fill flush using colourfill (https://colorfill.co.uk/), which is flexible, in a colour to match the worktop?

I've just used slivers for my floorboards and they worked really well. Would recommend.

How about this?

youtube.com/watch?v=TBgV0EkjWEw&

Colourfill doesn't appear to be terribly flexible at all, certainly nowhere near as much as silicone.  I've just used it fitting worktops in my Dad's kitchen a week ago - run a bead along the exposed edge of the worktops, wind up the butterfly bolts to close the gap then wipe off the excess that's squidged out.

thanks all for replies. sorry got distracetd by work/children/life for a week after first posting.

should have sad that it's two oak worktops joined with biscuits (no bolts) but the fitter left this small gap. so i can't take apart or put any t-bar in.

like the sound of the cork board though so that i can cram some in then pack more filler on top, or the amrine caulk mentioned.

i did also try the  sawdust and glue but that crumbled also - specialist glue is mentioend for this, any named suggestions? i only used PVA so maybe that's where i went wrong. I guess the fitter left a small gap to allow expansion/contraction over the year (or he was just a bit crap, no idea). 

i think the wood slivers are too thick for this tiny sized gap unfortunately!

A bit crap.  Wood expands across the grain, not the length, and the amount of expansion is determined by changes in moisture content of the wood. A sealed (varnish or hardwax oil) worktop doesn't expand much at all. It should have been glued up as tightly as possible and held down by slotted brackets that allow movement across the grain.

ah, this is something else i didn't make clear then originally - the gap is lengthways along two worktops put together side by side, rather than end to end. so i guess the gap is maybe needed after all to allow sideways grain expansion. 

Bit of a bodge but Mapesil (available from Screwfix) do coloured silicone sealants. They're matched to grout colourings, but do have a few different brown shades available. It seems a bit more mobile than other sealants, so should penetrate the crack deeper than filler. Really good mould resistance too, (used it in two shower enclosures at home).

Only if the outer edges of the worktops can't expand into free space i.e. the worktops are in a gap between two walls (like a wooden floor is). If it's an 'island'-type affair then they should have been tightly butted up.

Hmmm thanks. Yes there is room either side - not an easy undertaking to remove one worktop and really get it tight to the other one though. I’ll try the flexible coloured sealant mentioned before I get that serious.