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Screwing into aluminium.

Posted: Sun Feb 14 2021 20:19
by 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? :shrug:

Re: Screwing into aluminium.

Posted: Sun Feb 14 2021 20:26
by Andrew
John Milford wrote: Sun Feb 14 2021 20:19 -
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? :shrug:
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

Re: Screwing into aluminium.

Posted: Sun Feb 14 2021 20:36
by John Milford
Andrew Croft wrote: Sun Feb 14 2021 20:26 -
John Milford wrote: Sun Feb 14 2021 20:19 -
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? :shrug:
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! :eek:

Re: Screwing into aluminium.

Posted: Sun Feb 14 2021 20:44
by Andrew
John Milford wrote: Sun Feb 14 2021 20:36 -
Andrew Croft wrote: Sun Feb 14 2021 20:26 -
John Milford wrote: Sun Feb 14 2021 20:19 -
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? :shrug:
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! :eek:
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

Re: Screwing into aluminium.

Posted: Sun Feb 14 2021 20:47
by Cyprio
8mm self tapper :laughs:

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 :wink:

Re: Screwing into aluminium.

Posted: Sun Feb 14 2021 21:29
by John Milford
Cyprio wrote: Sun Feb 14 2021 20:47 -
8mm self tapper :laughs:

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 :wink:
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. :shrug:

Re: Screwing into aluminium.

Posted: Mon Feb 15 2021 12:03
by Mike J
John Milford wrote: Sun Feb 14 2021 21:29 -
Cyprio wrote: Sun Feb 14 2021 20:47 -
8mm self tapper :laughs:

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 :wink:
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. :shrug:

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

.

Re: Screwing into aluminium.

Posted: Mon Feb 15 2021 13:15
by 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. :cool:

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!. :wink: ).

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).

Re: Screwing into aluminium.

Posted: Mon Feb 15 2021 13:32
by spincityfan
Mike J wrote: Mon Feb 15 2021 12:03 -
John Milford wrote: Sun Feb 14 2021 21:29 -
Cyprio wrote: Sun Feb 14 2021 20:47 -
8mm self tapper :laughs:

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 :wink:
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. :shrug:

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

.
That's what I would do too.

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

Re: Screwing into aluminium.

Posted: Mon Feb 15 2021 13:35
by davelumb
Can you not effect a 'no screws' solution using Jubilee Clips or something? Or would that offend your tackle tart's sensibilities? :giggle:

Re: Screwing into aluminium.

Posted: Mon Feb 15 2021 13:47
by John Milford
davelumb wrote: Mon Feb 15 2021 13:35 -
Can you not effect a 'no screws' solution using Jubilee Clips or something? Or would that offend your tackle tart's sensibilities? :giggle:
I'm having palpitations at the very thought . . . ! :afraid:

Re: Screwing into aluminium.

Posted: Mon Feb 15 2021 13:48
by davelumb
John Milford wrote: Mon Feb 15 2021 13:47 -
davelumb wrote: Mon Feb 15 2021 13:35 -
Can you not effect a 'no screws' solution using Jubilee Clips or something? Or would that offend your tackle tart's sensibilities? :giggle:
I'm having palpitations at the very thought . . . ! :afraid:
You don't fancy the gaffer tape solution? :joker:

Re: Screwing into aluminium.

Posted: Tue Feb 16 2021 01:08
by andrew_nagel
.

Re: Screwing into aluminium.

Posted: Wed Feb 17 2021 09:53
by Bucks Andy
John Milford wrote: Sun Feb 14 2021 20:19 -
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? :shrug:
John. What size thread are you looking to tap. I have a box full of taps and can send whatever you need.

Re: Screwing into aluminium.

Posted: Thu Mar 04 2021 19:09
by Kev Berry
davelumb wrote: Mon Feb 15 2021 13:48 -
John Milford wrote: Mon Feb 15 2021 13:47 -
davelumb wrote: Mon Feb 15 2021 13:35 -
Can you not effect a 'no screws' solution using Jubilee Clips or something? Or would that offend your tackle tart's sensibilities? :giggle:
I'm having palpitations at the very thought . . . ! :afraid:
You don't fancy the gaffer tape solution? :joker:
and whats wrong with electricians tape? (cheaper :wink: )

Re: Screwing into aluminium.

Posted: Thu Mar 04 2021 19:26
by davelumb
Kev Berry wrote: Thu Mar 04 2021 19:09 -
davelumb wrote: Mon Feb 15 2021 13:48 -
John Milford wrote: Mon Feb 15 2021 13:47 -
davelumb wrote: Mon Feb 15 2021 13:35 -
Can you not effect a 'no screws' solution using Jubilee Clips or something? Or would that offend your tackle tart's sensibilities? :giggle:
I'm having palpitations at the very thought . . . ! :afraid:
You don't fancy the gaffer tape solution? :joker:
and whats wrong with electricians tape? (cheaper :wink: )
Whichever you have to hand will do. :thumbs:

Re: Screwing into aluminium.

Posted: Thu Mar 04 2021 19:32
by John Milford
Drilling a pilot hole and driving a steel self-tapper into it worked. I lubricated the screw with WD40 and backed it off every half turn, before driving it further in. That took a bit of patience, but it paid off.

Fixing the rubber lined metal P clip to take the 8 mm X 10 cm accessory rod was straightforward on the first two rests.

The third was a b@$t@®d and I broke two HSS drill bits and one screw on it! 😤 Sorted it in the end though. :thumbs:

Re: Screwing into aluminium.

Posted: Thu Mar 04 2021 19:59
by Pikerd74
John Milford wrote: Thu Mar 04 2021 19:32 -
Drilling a pilot hole and driving a steel self-tapper into it worked. I lubricated the screw with WD40 and backed it off every half turn, before driving it further in. That took a bit of patience, but it paid off.

Fixing the rubber lined metal P clip to take the 8 mm X 10 cm accessory rod was straightforward on the first two rests.

The third was a b@$t@®d and I broke two HSS drill bits and one screw on it! 😤 Sorted it in the end though. :thumbs:
Keep checking them John ally and steel tend to react and corrode, stainless steel is ok though :thumbs:

Re: Screwing into aluminium.

Posted: Thu Mar 04 2021 21:29
by John Milford
Pikerd74 wrote: Thu Mar 04 2021 19:59 -
John Milford wrote: Thu Mar 04 2021 19:32 -
Drilling a pilot hole and driving a steel self-tapper into it worked. I lubricated the screw with WD40 and backed it off every half turn, before driving it further in. That took a bit of patience, but it paid off.

Fixing the rubber lined metal P clip to take the 8 mm X 10 cm accessory rod was straightforward on the first two rests.

The third was a b@$t@®d and I broke two HSS drill bits and one screw on it! 😤 Sorted it in the end though. :thumbs:
Keep checking them John ally and steel tend to react and corrode, stainless steel is ok though :thumbs:
:point:

That's reminded me of the Nuffield Physics I learned at school. (I must have a good memory as it was nearly fifty years ago! :eek: ).

Galvanic corrosion. Should be OK, provided there isn't a corrosive electrolyte (like water) bridging them. Like you say, worth checking and maybe inserting a smear of epoxy if there are any signs at some time in the future. :thumbs:

Re: Screwing into aluminium.

Posted: Thu Mar 04 2021 21:30
by Lukemilnes
You can also get a self driving scrw with a bladed head called a tech screw.(wafer head) . I use em on metal framed ceilings and partitions shop fitting. They'll drive into pretty much anything, really useful little things.

Make sure you use a Philips bit not a pz otherwise you'll slip and take a chunk out your thumb!

Re: Screwing into aluminium.

Posted: Fri Mar 05 2021 09:24
by Pikerd74
John Milford wrote: Thu Mar 04 2021 21:29 -
Pikerd74 wrote: Thu Mar 04 2021 19:59 -
John Milford wrote: Thu Mar 04 2021 19:32 -
Drilling a pilot hole and driving a steel self-tapper into it worked. I lubricated the screw with WD40 and backed it off every half turn, before driving it further in. That took a bit of patience, but it paid off.

Fixing the rubber lined metal P clip to take the 8 mm X 10 cm accessory rod was straightforward on the first two rests.

The third was a b@$t@®d and I broke two HSS drill bits and one screw on it! 😤 Sorted it in the end though. :thumbs:
Keep checking them John ally and steel tend to react and corrode, stainless steel is ok though :thumbs:
:point:

That's reminded me of the Nuffield Physics I learned at school. (I must have a good memory as it was nearly fifty years ago! :eek: ).

Galvanic corrosion. Should be OK, provided there isn't a corrosive electrolyte (like water) bridging them. Like you say, worth checking and maybe inserting a smear of epoxy if there are any signs at some time in the future. :thumbs:
That’s the one John it happens on alloy wheels where that sit on a steel hub causing them to corrode and seize on ,very annoying with a flat tyre at the side of the road in winter :sad:

Re: Screwing into aluminium.

Posted: Fri Mar 05 2021 12:03
by Carlperkins
A tip off the AA man
Loosen bolts and drive backwards and forwards a few yards then Jack up the car.
👍

Re: Screwing into aluminium.

Posted: Fri Mar 05 2021 12:09
by Pikerd74
:thumbs:
Carlperkins wrote: Fri Mar 05 2021 12:03 -
A tip off the AA man
Loosen bolts and drive backwards and forwards a few yards then Jack up the car.
👍
I have been told never to smear copper grease on your hubs if you have alloys because that can react too! It’s ok on steel wheel on the boat trailer though
:thumbs:

Re: Screwing into aluminium.

Posted: Fri Mar 05 2021 12:21
by Carlperkins
👍

Re: Screwing into aluminium.

Posted: Mon May 31 2021 23:54
by colinb
Bottas's Mercedes alloy wheel took 43 hours to separate from the rest of the car 😁😁😁

Re: Screwing into aluminium.

Posted: Fri Jun 25 2021 20:10
by tigger996
Rivnuts