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https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl DIY Forum >> Carpentry Questions >> m d f and screws https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl?num=1103506278 Message started by big_all on Dec 20^th, 2004, 1:31am

Title: m d f and screws
Post by big_all on Dec 20^th, 2004, 1:31am

when i secure into the end of 12mm m d f i drill a 3mm pilot hole i use 6by2" normal twin wood screws
just wondering if anybody has used some of the other sorts of screws with sucsess with minimal delamination of the mdf and do the heads pull in without countersinking ??? ???

Title: Re: m d f and screws
Post by dj on Dec 20^th, 2004, 4:42am

hey ba, don't slate me for this because i aint a joiner.
will the pro turbogold do the job??
i use em but i don't know if they will do what you want.

if/ when you find your answer could you let me know??

Title: Re: m d f and screws
Post by big-e on Dec 20^th, 2004, 5:13am

The turbo ultra are the ones to go for, they are the same as the gold but stainless with the added bonus of not being threaded the entire length of the shank on the larger sizes which is better for pulling together when not pre-drilling. A bit pricey but worth it as I have not split anything as of yet, mdf, pine, mahogany and maple. If too expensive then invest in a set of flip drivers and all your troubles will be over. :)

Title: Re: m d f and screws
Post by jasonB on Dec 20^th, 2004, 7:46am

I also pilot the edge of MDF but don't recall screwing into the edge of any 12mm. For hinges into 18mm I use 3.5mm screws with a 2.5 pilot, keep the screws as long as possible. For holding 18mm carcases together I use screwfix's Powerdrives, 4mm clearance & CSK, 3mm pilot into endgrain & biscutes. I have also resorted to drilling for 5mm dowels, glueing them & screwing into those.

I doubt that the turbos etc will be anygood into the side of MDF but work well into the face.

Keep the screws as far from the ends of the board as possible.

Jason

Title: Re: m d f and screws
Post by jasonB on Dec 20^th, 2004, 1:18pm

Just tried a 5.0x60 stainless turbo into the edge of an 18mm board with no pilot, started to delaminate before the screw had penetrated 10mm!

Jason

Title: Re: m d f and screws
Post by big_all on Dec 20^th, 2004, 1:39pm

thank dj ive tried gold but not turbo gold[i would never critisize anybody d j giving usefull suggestions just thanks] ;D ;)

thanks big e do they split [delaminate the layers when screwing into the end grain near to the corner!

thanks jason i use mdf to make cupboard carcassing ect and securing the shelve and carcasses with scews and glue where battons cannot be used!

just trying to remove the tedium of countersink pilot then screw
as it happens you dont need to use a countersink bit just use srewdriver bit its perfect size for no6 screws

and thanks for trying a turbo gold jason its just cleared that bit up

Title: Re: m d f and screws
Post by woodsmith on Dec 20^th, 2004, 3:55pm

For MDF I use the powerdrive screws same as Jason, if you need a shorter screw then dry lining screws work well. If I need a really strong joint then Confirmat screws (from Woodfit for instance) work very well.

I am not really impressed with the stainless turbo screws, they snap at every oportunity. If you need posidrive then the stainless Spax screws sold by Axminster are much better IMHO.

Screwfix also sell slotted stainless screws not so good with a drill driver but very good quality never had any problems with them when used with timber no use for MDF though.

Keith

Title: Re: m d f and screws
Post by dj on Dec 20^th, 2004, 4:56pm

it just happens my spot board is 12mm mdf so i have tried one of the turbogold and it split after about four turns. tried it away from the edge and it still split. so in answer the turbogold won't do it.

Title: Re: m d f and screws
Post by big-e on Dec 20^th, 2004, 6:27pm

Sorry guys, I didnt see the bit about screwing into end grain on mdf( it was 5am after all) I only use it to top shelves in wardrobes/cupboards etc. or maybe make doors but always use concealed hinges so havnt really tried end grain :)
I must admit that I've never snapped one yet though ??? must be lucky.

Title: Re: m d f and screws
Post by jasonB on Dec 20^th, 2004, 8:07pm

I only bought the SS ones for a specific job but did manage to snap a few heads off, don't know about the plated ones.

Jason

Title: Re: m d f and screws
Post by big_all on Dec 20^th, 2004, 8:30pm

thanks again men [and womem] still not shure if i can screw without a pilot hole ??? ??? ??? ???
think i will start on the beer will make my brain think clearer;D ;D ;)

Title: Re: m d f and screws
Post by jasonB on Dec 20^th, 2004, 8:44pm

Pilot is the only way into side of board, diameter same as the root of the screw (think thats the term) and use fully threaded screws.

I use one drill with clearance/csk snappy bit and another with pilot snappy and change to snappy magnetic screwdriver bit. Makes life a bit easier, bench gets too cluttered if I use 3 cordless at the same time.

Never liked the clearance hole from flip-over bits as you cannot vary it for the depth of wood so I use these in 4,5 & 6mm http://www.tooled-up.com/Product.asp?PID=32603 and the SF hex recess bits in smaller sizes for pilot into second piece of wood.

Jason

Title: Re: m d f and screws
Post by woodsmith on Dec 20^th, 2004, 9:23pm

wrote on Dec 20^th, 2004, 8:30pm:

thanks again men [and womem] still not shure if i can screw without a pilot hole ??? ??? ??? ???
think i will start on the beer will make my brain think clearer;D ;D ;)

Do you know something I don't, which of us is female, just looked and it isn't me :o ;D

Title: Re: m d f and screws
Post by big_all on Dec 20^th, 2004, 9:27pm

thaks jason

i am just surprised there is not a specialist mdf screw that wont delaminate the mdf
i think the actual clearence or a no 6 screw is 3.2[1/8"]so the 3mm is a bit tight if i am neer the end and cant find a3.2mm i just use a 3.5 pilot hole push glue into the hole and screw in which gives you maximum grip
as i say a 3mm gives the maximum possible grip with least effort
just like you want to use the least possible no of drills for ease of assembly

surprised nobodys developed a multihead r/angled screwdriver where you hold it verticaly drill the pilot rotate in your hand a quarter turn countersink another quarter turn screwin another quarter turn shot off ouzo another quarter turn start again ::) ::) ;)

Title: Re: m d f and screws
Post by big_all on Dec 20^th, 2004, 9:31pm

wrote on Dec 20^th, 2004, 9:23pm:

Do you know something I don't, which of us is female, just looked and it isn't me :o ;D

bad to make assumption keith and women deserve the same respect as every body else ::) ;D ;)

like you kieth i wasnt female last time i looked but who knows tommorow is a differant day ;D ;D ;D ;D ;D

Title: Re: m d f and screws
Post by missmolly on Dec 20^th, 2004, 9:53pm

Hi BA

Its good to know there is respect for women!

Last time I checked - 10 minutes ago I was one ;D

I don't post much - but I lurk-a-lot.

Brilliant site though - but needs more women :D

Title: Re: m d f and screws
Post by Kesh on Dec 21^st, 2004, 12:26am

I generally try to avoid screws into the end of MDF - cranked hinges/battens/modesty blocks, or whatever to avoid it.

If it is essential then always drill a pilot. If it does split, a touch of "no-nails" rubbed into the split should solve the problem.

Title: Re: m d f and screws
Post by big_all on Dec 21^st, 2004, 12:48am

wrote on Dec 20^th, 2004, 9:53pm:

Hi BA

Its good to know there is respect for women!

Last time I checked - 10 minutes ago I was one ;D

I don't post much - but I lurk-a-lot.

Brilliant site though - but needs more women :D

heeelllooo mis moly youve been a bit quiet of late ::) ::)

to be honest i do treat men and women differently i dont want to but if you use the same small talk on men they think your chatting them up ;D ;D ;D ;D ;)

Title: Re: m d f and screws
Post by Dewy on Dec 21^st, 2004, 1:55am

I wish Plasplugs still made those chipboard plugs that glue in the ends of boards.
They made a much better fixing for screws and might be ideal for MDF.
They stopped making them about 1990 and when I found out I went round every local DIY shed and hardware shop buying up all they had in stock.
I got a bargain at B&Q as they sold me the last 12 strips for the price of 1 -40 plug strip.

Title: Re: m d f and screws
Post by jasonB on Dec 21^st, 2004, 7:31am

Have only used them when I need to use a standard screw into pre drilled carcases but may do the job, will try one later & let you know.

http://www.woodfit.com/product_info.php?products_id=1184&Name=Chipboard+Fastener+-+12mm+-+Nylon

Jason

Title: Re: m d f and screws
Post by jasonB on Dec 21^st, 2004, 5:47pm

Don't bother with them, split before I had tapped it all the way in!

JB.

Title: Re: m d f and screws
Post by woodsmith on Dec 21^st, 2004, 11:16pm

I used something like that years ago found that it was difficult to get the hole just right either split the board or pulled out.

One fixing I have found useful is the M6 insert nut which allows the fixing to be dis-asssembled and re-assembled with no loss of strength.

http://www.screwfix.com/app/sfd/cat/pro.jsp?ts=70900&id=28157

Title: Re: m d f and screws
Post by big_all on Dec 22^nd, 2004, 12:24am

thanks again for all your help people i have come to the conclusion as mdf is close pressed fibbers the only fixing that will work is one that doesnt displace more than 10% of the screw area and certainly wont work without a pilot hole as any screw will have to deflect the layers of the mdf because they cant deflect or compress the material
so unless there is a screw that can remove the material quicker than the screw goes in [imposible i think ;)]i will have to keep drilling and countersinking :-X :-/ ;D ;)

Title: Re: m d f and screws
Post by woodsmith on Dec 22^nd, 2004, 7:51am

One other thing when I am having problems with the MDF splitting, like on a narrow section (not necessarily a thin one), I use a G clamp to keep the MDF compressed still need to pre drill though, while driving in the screw.

Title: Re: m d f and screws
Post by big_all on Dec 22^nd, 2004, 12:26pm

funny enough keith thats one of the solutions i worked on too if the mdf delaminates when screwing take the screw out fill with glue put the screw in a few tuns[to stop the glue comming out]clamp tightly then screw home firmly

another point i alway slightly undertighten with the drill and finnish by hand because over tightening will again delaminate the mdf

Title: Re: m d f and screws
Post by woodsmith on Dec 22^nd, 2004, 12:50pm

BA you need to get that clutch under control ;D

Title: Re: m d f and screws
Post by john_elliott on Dec 22^nd, 2004, 1:37pm

I don't know if it would be applicable here, but some joints, such as shelves to uprights, can be made quite well with pocket screws, this way the screw is going into the side of the upright, rather than into the edge of the shelf. Much less troublesome.
John

Title: Re: m d f and screws
Post by Seaco on Mar 6^th, 2005, 12:08am

You could try just plain plastic rawl plugs countersunk into the end grain which may limit the amount of expansion in the MDF?... :-*

Title: Re: m d f and screws
Post by big_all on Mar 6^th, 2005, 11:44pm

heeelllooo seaco and welome thank you for your comments

in general i was looking for minimum operations [movements]with maximum results will try plugs and fingers crossed may help but suspect the plugs may still delaminate the layers
but thanks for the suggestion i will try it

Title: Re: m d f and screws
Post by HM on Mar 7^th, 2005, 12:15am

This probably won't do what you are looking for, but I'll mention it anyway.

You can get cam locks and cam dowels like the following from screwfix. These are what are used in all the finest MFI furniture for connecting cupboard shelving to uprights, so depending upon your application they might be a possibility?

HM

Title: Re: m d f and screws
Post by WOLF on Mar 8^th, 2005, 12:38am

Okay guys (and girls-well someone mentioned them!)
MDF screws, if you must use that dreaded material(me included lately) then why not try MDF screws, and here is the link!!!!http://www.quickscrew.com/screwmdfcskphillps.html .. and yes i have used these, pilot holes a must .. read later in this posting

now then HM, the cam and dowel fixing is designed specifically for use in chip board type substrates due to the deep thread upon the dowel section, and would delaminate the mdf very rapidly,

as for mdf fixings anyways, i once was given a fact sheet from one of my suppliers, which stated that any screw fixing must be countersunk, using pre drilled and piloted holes, due to the complete lack of compression available from the material...
hopefully this will help you guys(and girlies)
best regards 8) 8) 8)

Title: Re: m d f and screws
Post by jasonB on Mar 8^th, 2005, 7:43am

Wolf

"Has a sharp spiral point allowing it to pierce the hard surface"

Thats OK for going into the surface, but the thead was about fixing into the side of 12mm board these look like they would expand it more than the powerdrives which have a thinner core diameter.

HM the cams need a hole deeper than the 12mm board :-[ But the dowels do work in MDF, fitted many a MDF endpanel to flat pack kitchens with these but the do need a 5mm pilot hole or you can get ones with an expanding end.

Jason

Title: Re: m d f and screws
Post by WOLF on Mar 8^th, 2005, 12:59pm

i stand corrected upon the dowel /cam, i have always been advised by my suppliers NOT to use in end of mdf panels, as for the screws, they work for me, if you have any doubts why not give quickscrew a ring, and speak to them!!! :o