Drywall Screws - Fine Thread

Excerpt from my blog: http://www.lkorailroad.com/backdrops-part-i/

I found that drywall screws can’t reliably be used in hardboard as you would in sheet rock. Without a countersink either the screw won’t pull down into the hardboard without stripping or when the stud is tight wood the head of the screw often blows right off when the drill gets a good bite on the screw. I ended up countersinking all the screws. Word to anyone that uses their countersinking bit on hardboard – it wears out fast. The countersink actually worked best when it did get a little dull. With the hardboard only 1/8″ thick it was tedious at times to get sufficient sink without removing too much depth and having the screw pull right through. A dull countersink gave a little more control of the depth simply because it cut much slower. Anyway, another half bucket of drywall screws consumed.

Countersink

Alan,

I'm using 1-1/4 wood screws which is probably my first mistake.  I tried not countersinking just drilling a pilot hole and the screw head still tore right thru.  I think using tempered back 1/8" is a mistake.  It was $5.87 for the 4x8 so I'm willing to start over with solid 3/16".   Just hope I can get the ease of flex with it as the 1/8".

James

Wrong Screws

1/8" tempered is not a mistake. Look at my blog. I have successfully mounted over 100 running feet of it without issue.

Using wood screws is your problem. The taper under the head is too deep and the shank is too large. Drywall screws have a large head relative to the shank diameter which is what you need for hardboard sheet. Countersinking removes the necessity of drawing the screw down into the hardboard by force (which is difficult to control accurately).

Drywall Screws

Ok I'll try the drywall screws...what size did you use?

Also I will have to re-think my countersink bit.  I use a quick change type which may be too aggressive.  The one you show looks finer/thinner.

James

Screws

#6 x 1-5/8" You could use shorter. I just happen to have a bucket of this length. Screws at Home Depot. I like fine thread because it gives me greater setting depth control with the drill.

The reason I like this particular countersink model is twofold - it is self-drilling, no pilot drill needed and the collar allows you to set the sink depth. That way all your sinks are the perfect depth. I switched to the collar style bit midway through my project to solve the issue I was having maintaining uniform sink depths noted in the original blog post.

Otther screw options

If it is acceptable for the screw heads to be visible there are some  other options to prevent the screws from pulling through.

Washer head screws are flat under the head and are larger in diameter than the usual head for the screw size.  However these may not be as available locally.  Another option could be pocket hole screws.  These also are designed with a flat head to prevent pulling through.  They are available with either coarse or fine threads depending on the type of wood - fine for hardwood, coarse for soft.

John

...

If you can back down the torque on your powerdriver, you may do that as well.

Success

I used #6 (1-1/4" ) drywall screws and these worked great.   One issue with 1/8" hardboard is countersinking the screw head.  I lightly ground out a hole with a drill bit slightly larger than the size of the screw head.  Then simply drove in the screw slowly...no pilot hole needed.

James

Success

Glad to hear you are having success.

A countersink is a good investment. They aren't expensive. The oversize drill bit works but is difficult to control the depth of sink. This is especially important in your application since the hardboard is only 1/8" thick. A pinch too little and the screw head sticks out above the surface of the hardboard. A pinch too much and the screw pulls through the hardboard. A countersink with depth collar totally eliminates these possible issues making installation faster, more uniform, and foolproof.

mounting Masonite

I took a different approach.  I bought some countersink washers at a big box store.  I paid about $0.79 for 14 brass ones.  They have the advantages that there are no screw heads to snag on clothing, plus they act like bumpers so walking operators don't get so close the the layout that they clip something with an elbow.

Here's a link:

http://www.google.com/search?q=countersink+washers&rlz=1C1RNBN_enUS460US466&oq=coun&sourceid=chrome&ie=UTF-8

Paul E. Sojka

I cheated

On the backdrops for the latest incarnation of the M&WV, I used.....small nails. Yes, those little fellas held up just fine and you can paint right over them. From previous issues, I knew better than to use screws in my Masonite, as they tend to tear it to shreds. They're 3/4" x 18 Wire Nails.