Frustrated and in need of help

[ol trunt]

It makes no sense to have the tech screws threading into the wood. All that is going to do is cause the wood to lift as the screw tip hits the metal. Even if the screw does finally penetrate the metal there will still be space between the wood and metal and the wood will seem lose even with the screw head flush with the wood. To then get the wood tight will require the screw to strip out the threads in the wood so the screw can finally pull the wood to the metal. A hammer drill may help with this but since there is way more thread contact with the wood, either the screw threads themselves where they go through the metal or the metal itself are very likely to strip.

Drill a pilot hole of the proper size for the tech screw through both the wood and the metal and then enlarge the hole in the wood to a size that lets the tech screw drop freely to the metal through the wood. When actually tapping the metal with the tech screw use a drill speed just fast enough to allow for the tech screw to cut. Too fast a speed will suddenly bottom out the screw and either strip it or break off the head.
Jack

[BamaBus]

Are you hitting the frame under the floor?

[CHEESE_WAGON]

Originally Posted by BamaBus

Are you hitting the frame under the floor?

Same thing I was saying, in addition to...

Originally Posted by ol trunt

It makes no sense to have the tech screws threading into the wood. All that is going to do is cause the wood to lift as the screw tip hits the metal. Even if the screw does finally penetrate the metal there will still be space between the wood and metal and the wood will seem lose even with the screw head flush with the wood. To then get the wood tight will require the screw to strip out the threads in the wood so the screw can finally pull the wood to the metal. A hammer drill may help with this but since there is way more thread contact with the wood, either the screw threads themselves where they go through the metal or the metal itself are very likely to strip.

Drill a pilot hole of the proper size for the tech screw through both the wood and the metal and then enlarge the hole in the wood to a size that lets the tech screw drop freely to the metal through the wood. When actually tapping the metal with the tech screw use a drill speed just fast enough to allow for the tech screw to cut. Too fast a speed will suddenly bottom out the screw and either strip it or break off the head.
Jack

I think OP is experiencing a combination of these. I also think the screws are long enough that they are not able to sink the head completely into the wood.

[Native]

Originally Posted by ol trunt

It makes no sense to have the tech screws threading into the wood. All that is going to do is cause the wood to lift as the screw tip hits the metal. Even if the screw does finally penetrate the metal there will still be space between the wood and metal and the wood will seem lose even with the screw head flush with the wood. To then get the wood tight will require the screw to strip out the threads in the wood so the screw can finally pull the wood to the metal. A hammer drill may help with this but since there is way more thread contact with the wood, either the screw threads themselves where they go through the metal or the metal itself are very likely to strip.

Drill a pilot hole of the proper size for the tech screw through both the wood and the metal and then enlarge the hole in the wood to a size that lets the tech screw drop freely to the metal through the wood. When actually tapping the metal with the tech screw use a drill speed just fast enough to allow for the tech screw to cut. Too fast a speed will suddenly bottom out the screw and either strip it or break off the head.
Jack

The Tek screws being used have wings after the tapping head. These wings cut a hole in the wood the size needed to allow the screw to burry itself without actually screwing the wood and lifting the wood when it hits the metal. These are wonderfully engineered screws ... the metal floors in the bus are wonderfully hard to cut and take a lot of pressure to cut the tap for the metal screw threads.

[gussboy]

threr are specific screws , heavy duty ,kinda like screw used to fasten boards
onto flatbed trucks ,check local resource truck co. or rental yard

[BamaBus]

Originally Posted by CHEESE_WAGON

Same thing I was saying

I think you were right and that was the idea I was trying to reinforce without mucking it up with other thoughts. Seems to me that a 3" screw is way too long if just trying to screw down plywood to a metal floor. Either hitting the frame rail or something else to make it stop with 1 inch to go. I see it hitting the rail and it is actually wanting to push back up against the metal floor, but it can't and that's why the drill stops.

[Danjo]

Originally Posted by BamaBus

I think you were right and that was the idea I was trying to reinforce without mucking it up with other thoughts. Seems to me that a 3" screw is way too long if just trying to screw down plywood to a metal floor. Either hitting the frame rail or something else to make it stop with 1 inch to go. I see it hitting the rail and it is actually wanting to push back up against the metal floor, but it can't and that's why the drill stops.

Those screws have a 3:4” long pilot metal cutting bit on the front, then the screw starts. The wood-to-metal screw has a fine thread that can screw through wood, but then quickly strips out in the wood. The pilot bit in the front can *almost* make it through 1/8” mild steel. So when you buy those screws they need to be 1” longer than the material that you want to screw

[witchywoman]

We got it! Last night I went and grabbed an impact driver. And today...voila! Screws went in and are seated perfectly. It was actually pretty simple nice we learned the tool we needed. Thanks everyone!

[witchywoman]

We were screwing the plywood down on top of insulation so I allotted for leaving 1/2” on the underside of the bus. The 2 sheets we put down are sitting nice and firm.

[Native]

Excellent!!!

[CHEESE_WAGON]

Originally Posted by witchywoman

we got it! Last night i went and grabbed an impact driver. And today...voila! Screws went in and are seated perfectly. It was actually pretty simple nice we learned the tool we needed. Thanks everyone!

Originally Posted by witchywoman

we were screwing the plywood down on top of

[s2mikon]

Here is what I used. https://www.ebay.com/itm/50-1-4-20-X...AAAOSw4HVWEXMF


Pre-drill 3/16 and use a t-30 torx bit on a electric impact gun. I used about 300 of them. I have no monetary interest in the evil-bay seller.

[Rubicon58]

After a lot of money and trial and error this is what I’m using. PowerPro One Multi-Material by Hillman. Lowe’s carries this in stock. Pre-drill and you should be fine.

[gussboy]

bypass useless opinions ,here the straight dope ,me retired builder .
have worked on mobile homes trailers, what exactly is dimension in
thikeness of woo ,and metal below?
And is metal below 1/8 inch sheet metal oir are you drillin into frame rails
you must use proper fastener , Fastech .com
use a screw that is made for wood on top metal below of sufficent
length to go through wood {passing thru.pullin down}
and of proper diameter ,to thread into sheet metal /NOT STRIP OUT.
also sometime must use pilot srew hole {metal BIT} 1/8 smaller then screw size
Also buy a dewalt brushless impact driver .you need the power to
do the work
the screws shown on your post are average deck screw NOT good enuf.

I hope this help gussboy ,see my bus#10 crown

[Rubicon58]

I have built homes and rebuilt cars for over 40 years. The fastener I’m using in my Skoolie is an awesome fastened. I doubt you have used this fastener for anything to please refrain from your insults. Thank you.

[gussboy]

sorry if you feel insulted ,ive got ,nothing to add

[Rubicon58]

Whatever, dude.

[musigenesis]

Originally Posted by Rubicon58

I have built homes and rebuilt cars for over 40 years. The fastener I’m using in my Skoolie is an awesome fastened. I doubt you have used this fastener for anything to please refrain from your insults. Thank you.

I don't think the other user meant you specifically with their "bypass useless opinions". I think they were referring to everyone else here with an opinion. One feature of skoolie.net that can really improve the experience on this forum is the ignore list. Click on User CP in the upper left and then click on "edit ignore list". You can then add users to the list and their posts are automatically hidden from you.

[Rubicon58]

Thank you for the heads up. I will do that.

[gussboy]

the screw a very experienced person is showing is not a flush finish bugle head screw
do you think a flat smooth surface is good for a floor
me 50 years exp.