Surely these are only 'self drilling' in the basic sense of cutting their own thread - they still need a pilot hole through the steel to thread in to?
How thick is this steel box that you have to go through? I’ve got some black self tappers that are for fixing plasterboard to Zed channels etc <<< pun intended. These will very easily with pressure drill through and self tap quicker than I can drill an eighth hole in the frame work / can’t rails of my early sometimes even through a double layer and more. They are so good and so cheap that tossing the odd one out to one side ain’t an issue. If it’s more substantial than that I’d thoroughly recommend loads of mechanical leveridge, physical leverage is time consuming, tiring and for the most part negligible in effectiveness. There will be an easy way even if you’re levering off the other side. Plenty of leverage and a nice slow speed, funnily enough, oil if you can get it on the cutting / drilling surface really does help, a bit harder on vertical and almost impossible on upside down holes. That fulcrum point could be a four by two onto the same box section on the opposite side of the boat, maybe with some sort of spreader and a couple of large axle stands or even chairs or beer crates to keep it at the right height. With this sort of leverage you’ll drill eighth to quarter holes like counting ,one, two, three, it really is. That drill there, you are more than welcome to borrow and it’ll drill everything on your boat and the whole marina, just so long as you spin the motor occasionally with no load. So drill your hole spin the drill then on to the next. Ozziedog,,,,,,,,,,,, or a magnetic grab drill
I'm no stranger to drilling holes in steel Ozzie. I used to fit steel windows and on one job we had to drill and tap a zillion holes through 1/2" steel bar. That one we could grab around and do a squeeze on it. I got tennis elbow on that one but I could climb scaffolding just using my arms and do a couple of handstand press-ups. 40 years ago. lol That's why I know it's hard and looking for the easiest way. as per 1st post, it's 4-5mm mostly with a few 3mm parts for a rest.
Same here, I'm surprised that it works as described, must have to drill through the substrate very straight for the screw 'tip' to drill clean into the steel fixing. I'd imagine that anything less would have them going off at all angles and spinning around?
The self drilling screws will do it no problem don’t be tempted to get the stainless ones they just snap. Also I would get the bolt head ones rather then the pos dive as you can get a better grip I think they are 8mm and will still counter sink
Right @Zed - now you've got more options than you'll ever need, how about a photo to show the detail of the fixings you are needing to make, is your steelwork similar to the inside of a panel van, or are you looking to fix battens to steel plate?
I had to smash these off so I can prep the roof, but this kind of thing and vertical ones on the sides. Everything in this pic is gone or going. The sink/side hatch is in the part of the bathroom I'm turning into a corridor. I reckon the hull was made for this and someone thought they knew better, but I can tell you having a side hatch in the bathroom is beyond stupid. lol. Zoom inThe red primer steel is 5mm, you can see the end of a beam I cut through. It looks as thick or thicker I'd saay. I haven't measured it, there's no point in depressing myself so I'm calling it 4-5mm and wish to remain deluded. The lower side actually has battens... but being me I want to smash them off and treat the steel, them fit vertical ones, or perhaps a bit of both and end up something not like this but sort of.
I'm wondering in te last pic if the non-joining of the framework between lower side, upper side and roof is deliberate for expansion, the steel gets too hot too touch in the summer and below freezing in the winter.
Hard to believe it could end up nice at this point, but I know it will. Half this job is a continual clear out and tip runs. I'm chucking some perfectly good stuff to make room to do things in order without tripping over stuff I won't need until later. Just in time material purchasing is the name of the game with no storage.
Are the 'ribs' that you are wanting to fix the battens to, angle or box section? If angle, could something similar to Lindapters be used to save drilling the steel? There's bound to be a unistrut fitting that would do it too
Lindapters! I used them once to fit cable bracket in miles of the London Underground, forgot all about them... lower sides are angle but the rest is U channel, so not a great gain. Funny the stuff I used to specify to use thousands without even ever seeing them in the flesh. Bad designer, get in your box. lol Seriously thou London Underground by the time the lads went through all the saftey before and after each night they only had about an hour left so had to go like the clappers and Lindapters are fast.
https://www.globalwalkway.com/flooring-top-clip-only-galvanised That's a shame, as these grating top clips would of been a less 'heavy duty' version of lindapters
The ones I used were more like the girder ones, with teeth, cost a bomb but after the emergency services comms failure (uselessness) during the Kings Cross fire nobody much cared about the cost.
What was used previous? And what has been used in the new photo? Can you fit independent frames that fix to the ceiling frame and floor?
Are you gonna spray foam, or have spray foam done, on those areas you're exposing? Just a thought but if done properly it'll hold the battens in place once cured and you'll never have to worry about them again...
