MDF Table/Surface weight load

[OverConfidentNovice]

Hi

Quick query

Was given a surface-top portable dishwasher for Christmas but no space on kitchen surface as cupboards are too low

Have ordered 600mm x 400mm x 18mm MDF with moisture protection and 4x 90cm steel hairpin legs to make a temporary structure on which to keep the appliance.

Appliance weight is approx 15kg empty and probably 20kg filled.

Just want to check that the MDF & legs - which themslves should be ok for 45kg - will be enough to support the appliance - am just checking about structural integrity of MDF for that weight as am cobbling this structure together.

Thx

 

[freddiemercurystwin]

Yes no problem.

 

[OverConfidentNovice]

Yes no problem.

Thx

Also cats do indeed rule

 

[OverConfidentNovice]

Ok additional question.

Was pre-drilling into the MDF for pilot screw holes and the drill bit broke off too deep to recover. Have ordered some 3mm cobalt drill bits for other holes but not sure of best action to take other than repositioning the leg and the others to compensate.

 

[big-all]

you say3mm holes are the screw 3.2or 3.5mm?? Remember the thread is greater than the screw size

you must make sure the flutes are clear retract the drill 2 or 3 times to clear the flutes

as mdf is highly dense, it just compacts into the flutes and cause overheating and breaking

and the first time you go to clear the flutes you will burn your fingers and learn to use a screw point or other to clear

 

[OverConfidentNovice]

Issue is that the hole does not go through & out other side

It is a recess hole to attach legs onto bottom of the table unit

So will remove drill bit more frequently on the other holes but not sure how that one can be salvaged other than filling in & positioning leg slightly to the side

Legs are not on the exact edge but are 20mm in from edges/corners

 

[OverConfidentNovice]

you say3mm holes are the screw 3.2or 3.5mm?? Remember the thread is greater than the screw size

Screw shaft without threads 3mm so 3mm pilot hole

 

[OverConfidentNovice]

and the first time you go to clear the flutes you will burn your fingers and learn to use a screw point or other to clear

Ha very true but issue is that there is broken drill bit stuck deep in the hole

That is what am looking for potential solutions for now

 

[big-all]

3mm is an incredibly small screw have you got a link to the legs you are using ???
can you approach the drill bit from the other face ?? as in drill in till you reach the drill point then use a screw to push it out iff your lucky??

 

[OverConfidentNovice]

Just to clarfy 3mm is width & length is 16mm

Will link info about legs in moment

 

[freddiemercurystwin]

Just shift the legs one way or another by a few mm. Or if they are circular you can just rotate it.

@big-all I think the minor diameter of the screw is 3mm not the whole thread diameter.

 

[OverConfidentNovice]

MDF / table surface top is 18mm thick and legs are steel hairpin legs 90cm height

Screws provided with legs were 26mm length so am using 16mm length screws from own set with integrated washers

Legs are overkill for small surface size of MDF but 90cm was needed as using next to kitchen counter

Screws provided with legs were 4mm width inclusive of thread

Did not want to drill through if possible as would create a hole in the table top

Just shift the legs one way or another by a few mm. Or if they are circular you can just rotate it.

Did not think of rotating - might try a 180 first as screw holes would be automatically re-situated. Thx.

@big-all I think the minor diameter of the screw is 3mm not the whole thread diameter.

Correct

Thx both for for advice though - project is basic but is first which has not been a flat-pack

Was given a portable counter-surface dishwasher for Christmas but cupboards are too low in current bed-sit kitchen to fit under them so am making a temporary tailor-sized surface extension

 

[big-all]

my thoughts
are the screws provided 3mm??
my concern is the leverage and live load you need the maximum grip and size hole wise i suspect perhaps 4mm screws or larger
rather than go for what you have go for what was provided but perhaps 20-25 less value as redundant grip but only length wise so assuming a1mm thick bracket /leg you need 19mm screw off the same girth to have any chance so 20mm with the point ground off or 18mm
what size where the screw provided, i assume not 3mm??

 

[OverConfidentNovice]

my thoughts
are the screws provided 3mm??
my concern is the leverage and live load you need the maximum grip and size hole wise i suspect perhaps 4mm screws or larger
rather than go for what you have go for what was provided but perhaps 20-25 less value as redundant grip but only length wise so assuming a1mm thick bracket /leg you need 19mm screw off the same girth to have any chance so 20mm with the point ground off or 18mm
what size where the screw provided, i assume not 3mm??

Looks as though screws provided were M4 & 25mm in length but as initial question was re drill bits I was using a 3mm drill bit for pilot hole as per YouTube advice because the solid internal screw shaft sans threads was 3mm

MDF is 19mm thick so the 25mm long screws provided would have breached the top surface of unit when screwed up from bottom

Leg bracket is apparently 4mm thick (photo 3) & available screw set is shown below (photo 4). Theoretically an M4 20mm long screw should work if 19mm MDF plus 4mm bracket thickness = 23mm. Screw head diameter in my other screw set was too small & cleared through the holes in the bracket so had ordered the set with integrated washers for larger head diameter. I didn't know which serch terms to use for 'bigger headed' screws so screws with integrated washers was closest that I could find in next day delivery options on Amazon.

Hope that all makes sense

Hairpin legs are from Etsy:

https://www.etsy.com/uk/listing/1527321336/90cm35-premium-hairpin-legs-x2-or-x-4?ga_order=most_relevant&ga_search_type=all&ga_view_type=gallery&ga_search_query=90cm+hairpin+legs+steel&ref=sr_gallery-1-1&frs=1&local_signal_search=1&content_source=ef1329f8230e4edc7b6e944b321320c8dae60efd%253A1527321336&organic_search_click=1

And screws that was planning to use are from Amazon:

XxinXrong300 Pcs M3 M4 Cross Head Self Tapping Screws with Washers, Pan Head Self Drilling Wood Screws Assortment Kit, Round Countersunk Head Machine Screws Fasteners

Amazon.co.uk

I am open to ordering different screws as would rather do the job properly but am otherwise in over head with all the different screw types so yeah open to advice on which ones to get & from where

Possible screw alternatives could be M4 x 20mm Phillips Pan Head Wood Screwsor some 4x20 A2 screws but again cannot see head diameter for those

M4 x 20mm Phillips Pan Head Wood Screws Stainless Steel A2 DIN 7505B Pack of 20

Phillips pan head wood screws are designed for wood applications, featuring a flat, rounded head with a cross-shaped Phillips indentation. These screws are ideal for fastening materials where a low-profile, smooth finish is desired, commonly used in woodworking, furniture assembly, and various...

www.diy.com

Multipurpose Wood Screws A2 Stainless Steel

Chipboard Screws A2 Stainless Steel Finish: A2 Stainless Steel (anti-corrosion) Single thread, sharp point with a countersunk pozi head Stainless Steel Woodscrew The best screws for outdoor use are stainless steel screws. They are made of a material that is resistant to...

screwshop.co.uk

 

[big-all]

a couple of washers or grind the point off
stopping short to stop them showing on top is a gamble that will probably be fine