Screwing into aluminium.

[John Milford]

I plan to fit vertical bars for drop arm alarms on the aluminium clamps of my boat rod holders.

I've got some 8mm aluminium bar and P clips to attach it with, but I was wondering if I need to tap a thread for a machine screw for the P clip, or whether the metal is soft enough to put a self-tapping screw staight into after just drilling a pilot hole?

Anyone tried it?

[Andrew Croft]

I plan to fit vertical bars for drop arm alarms on the aluminium clamps of my boat rod holders.

I've got some 8mm aluminium bar and P clips to attach it with, but I was wondering if I need to tap a thread for a machine screw for the P clip, or whether the metal is soft enough to put a self-tapping screw staight into after just drilling a pilot hole?

Anyone tried it?

Used to drill a lot of self tapers in to ali, thin sheets though and 4mm steel. 8mm might need a pilot hole eh. Used to break a s**t ton of the screws

[John Milford]

I plan to fit vertical bars for drop arm alarms on the aluminium clamps of my boat rod holders.

I've got some 8mm aluminium bar and P clips to attach it with, but I was wondering if I need to tap a thread for a machine screw for the P clip, or whether the metal is soft enough to put a self-tapping screw staight into after just drilling a pilot hole?

Anyone tried it?

Used to drill a lot of self tapers in to ali, thin sheets though and 4mm steel. 8mm might need a pilot hole eh. Used to break a s**t ton of the screws

The hole won't be 8mm Croftus, that's just the diameter of the bar and size of the P clip.

I figured if I drill a pilot hole just slightly smaller than the screw thread size, a steel screw would cut its own thread?

The danger of snapping off the screw was the thing I was most concerned about!

[Andrew Croft]

I plan to fit vertical bars for drop arm alarms on the aluminium clamps of my boat rod holders.

I've got some 8mm aluminium bar and P clips to attach it with, but I was wondering if I need to tap a thread for a machine screw for the P clip, or whether the metal is soft enough to put a self-tapping screw staight into after just drilling a pilot hole?

Anyone tried it?

Used to drill a lot of self tapers in to ali, thin sheets though and 4mm steel. 8mm might need a pilot hole eh. Used to break a s**t ton of the screws

The hole won't be 8mm Croftus, that's just the diameter of the bar and size of the P clip.

I figured if I drill a pilot hole just slightly smaller than the screw thread size, a steel screw would cut its own thread?

The danger of snapping off the screw was the thing I was most concerned about!

Self tappers were a bloody nightmare. Made a nice bracket to hold my repurposed window wiper steering mechanism for my rc car last screw head comes clean of it pulled the heed of it many times

Maybe try do the last turn by hand

[Cyprio]

8mm self tapper

I would say you're be ok. Like you mentioned match the drill to the screw.
When I mounted my Scott'y bases to the Ali side of my boat I did tap a thread and fitted stainless bolts
my thoughts were it would make a stronger mount.
Depends how much metal you have to drill into. If it's not to wide use rivets

[John Milford]

8mm self tapper

I would say you're be ok. Like you mentioned match the drill to the screw.
When I mounted my Scott'y bases to the Ali side of my boat I did tap a thread and fitted stainless bolts
my thoughts were it would make a stronger mount.
Depends how much metal you have to drill into. If it's not to wide use rivets

The clamp I'm drilling into is about 10mm thick Andy I think I'll risk it.

I plan to modify three rod holders. If it doesn't work on the first one, the worst that will happen is I'll have a snapped off screw to file flush and then re-think.

[Mike J]

8mm self tapper

I would say you're be ok. Like you mentioned match the drill to the screw.
When I mounted my Scott'y bases to the Ali side of my boat I did tap a thread and fitted stainless bolts
my thoughts were it would make a stronger mount.
Depends how much metal you have to drill into. If it's not to wide use rivets

The clamp I'm drilling into is about 10mm thick Andy I think I'll risk it.

I plan to modify three rod holders. If it doesn't work on the first one, the worst that will happen is I'll have a snapped off screw to file flush and then re-think.

Do it once a do it right.
Tap a thread or drill a clearance for bolt, lock washer and nut.

.

[John Milford]

The rod holders are a set of four I purchased recently - the superb old school 'Taylor Engineering' ones, de riguer for the lads fishing W**r W**d, back in the day.

That's why my other perfectly good boat rod holders went in the 'For Sale' section - to offset my extravagant purchase! (One set still available!. ).

My regular fishing pal is a garage door engineer. He might have a set of taps to do a pukka modification.

(In case anyone is wondering, the adaptation to fit back alarms is not necessarily for boat fishing. I also plan to use the holders on the front board of some particularly tight platforms I sometimes fish from).

[spincityfan]

8mm self tapper

I would say you're be ok. Like you mentioned match the drill to the screw.
When I mounted my Scott'y bases to the Ali side of my boat I did tap a thread and fitted stainless bolts
my thoughts were it would make a stronger mount.
Depends how much metal you have to drill into. If it's not to wide use rivets

The clamp I'm drilling into is about 10mm thick Andy I think I'll risk it.

I plan to modify three rod holders. If it doesn't work on the first one, the worst that will happen is I'll have a snapped off screw to file flush and then re-think.

Do it once a do it right.
Tap a thread or drill a clearance for bolt, lock washer and nut.

.

That's what I would do too.

Self tappers can be hit and miss going into anything other than thin sheet IMO

[davelumb]

Can you not effect a 'no screws' solution using Jubilee Clips or something? Or would that offend your tackle tart's sensibilities?

[John Milford]

Can you not effect a 'no screws' solution using Jubilee Clips or something? Or would that offend your tackle tart's sensibilities?

I'm having palpitations at the very thought . . . !

[davelumb]

Can you not effect a 'no screws' solution using Jubilee Clips or something? Or would that offend your tackle tart's sensibilities?

I'm having palpitations at the very thought . . . !

You don't fancy the gaffer tape solution?

[andrew_nagel]

Maybe these are something to consider John. These are A2 M5 stainless (come in a range of sizes) and are used in welding when you need to fasten on a threaded component. The lugs are tacked in place and the threaded tubular section can either sit proud or be recessed through a drilled hole. I've used them a lot in my boats as a 'flush nut'. For example when fastening things to the helm with bolts, if a standard washer and nut was used I'd end up with nuts standing proud on the cabin ceiling to cut my head on! I just cut the bolts to length drill and insert one of these from the underside of the helm and bolt into it from above. It makes a flush fastening - very neat.
I've also used them from one side only by drilling a hole in the material to match the outer dia of the tubular section. Then epoxied them in place. When set I can bolt into them. Just a thought...

IMG_0838.jpeg

[Bucks Andy]

I plan to fit vertical bars for drop arm alarms on the aluminium clamps of my boat rod holders.

I've got some 8mm aluminium bar and P clips to attach it with, but I was wondering if I need to tap a thread for a machine screw for the P clip, or whether the metal is soft enough to put a self-tapping screw staight into after just drilling a pilot hole?

Anyone tried it?

John. What size thread are you looking to tap. I have a box full of taps and can send whatever you need.