Fastslappy
Well-Known Member
yeah AL chemically reacts into the disks ,wheels & explosive shards go everywhere .
It's Not a pretty picture
It's Not a pretty picture
trying to drill into my hs why do is it so hard
- Thread starter john0000
- Start date
churchhaze
Well-Known Member
I notice a huge difference in cutting speed when using carbide tipped bits. When I tried using one of my normal drill bits (that I use mostly for wood), it took me forever to get through the metal. I think it's totally worth using carbide tipped bits, even for aluminum.
whitebb2727
Well-Known Member
Take the bit and hold it next to what your drilling. Mark the bit with a sharpie. Make a dark ring around the bit or use a piece of tape. When you drill, stop at the mark. You won't damage anything.
whitebb2727
Well-Known Member
They make a machine to sharpen drill bits. I can do it by hand on a table grinder.
bicit
Well-Known Member
Drill press or hand drill?
My favorite is a #43 mechanic length, HSS, TiN coating. Mark the spot where you want to drill with a punch, helps starting considerably.
Slow and steady wins the race. Better to think about precision when drilling holes rather than speed.
Also, dont us masonry bits. Terrible results lol.
alesh
Well-Known Member
Yes, I do. If you don't and the bit goes through, it's very easy to break it when it hits the fin partially.
stardustsailor
Well-Known Member
Moreover ..
You do not have to drill all the way through ..
To attach a Vero series COB or a CXA/CXB holder a depth of about 6-8 mm is enough .
Crucial thing is to use stainless steel (INOX / ROSTFREI ) screws/washers ,in
order to avoid galvanic corrosion of Al .
Avoid galvanized or plain carbon steel screws.
Edit: Some M3 sized screws do not have markings on them .Best screws/washers for da job are made of austenitic Stainless Steel 18/8 aka 304 s.steel
(18% Cr -8% Ni )
A non-magnetic stainless steel with at least 7% nickel added.usually marked with " A2 "
Or screws marked " A4 " (316 s.steel ) Grade 316 is the standard molybdenum-bearing grade stainless steel, second in importance to 304 amongst the austenitic (non-magnetic) stainless steels. It is a surgical stainless steel. The molybdenum gives 316 better overall corrosion resistant properties than Grade 304, particularly higher resistance to pitting and crevice corrosion in chloride environments.
Avoid using Martensitic Stainless Steel screws ,as they are too hard and brittle.
They may -easily-destroy the tapped threads on Al and/or break ,if they are over-tighten .
Alloy 410 is a martensitic s. steel ,for example
Ferritic Stainless steel is magnetic and quite brittle also ,like the martensitic kind
Then ask to see the package / carton of the screws.
Always go for the A2 or A4 kind .
F1 ,C1,C4 & C3 screws need extra caution ,when you tighten or untighten them ..
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alesh
Well-Known Member
Great info. You have to drill all the way through if you have 8mm base and no bottoming tap
anyway I broke a tap or two this way so I felt it would be good to share.What do you think about aluminum screws?
stardustsailor
Well-Known Member
Aluminium screws are called " Ergal " or "Zicral " screws ( Al alloy 7075 ) and usually they are anodized with vivid colors .Great info. You have to drill all the way through if you have 8mm base and no bottoming tap
What do you think about aluminum screws?
Not very easy to find the M3 size ( which is extra prone to breakage ).
Also ergal screws corrode pretty easy ...
https://en.wikipedia.org/wiki/7075_aluminium_alloy
...................
Some more info about stainless steel I forgot to mention ....
Stainless steels are high-alloy steels. They have high corrosion resistance compared to other steels due to the presence of large amounts of chromium. Based on their crystalline structure, they are further divided into three types such as ferritic, austenitic, and martensitic steels. Another group of stainless steels are precipitation-hardened steels, a combination of martensitic and austenitic steels.Duplex steels are a combination of ferritic and austenitic steels, a structure which renders duplex steel stronger than both.
Ferritic – These steels contain less than 0.10% carbon and are magnetic. The fact that they can’t be hardened via heat treatment and don’t weld to a high standard limits the use of these metals somewhat, but they are still suitable for a wide range of applications.
Austenitic – This is the most common type of stainless steel, accounting for up to 70% of all stainless steel production. Its versatility is in large part down to the fact that it can be formed and welded with successful results.
Martensitic – This type of steel shares some characteristics with ferritic, but boasts higher levels of carbon, up to a full 1%. This means that they can be tempered and hardened and are thus highly useful in situations where the strength of the steel is more important than its resistance to corrosion.
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Another option but way expensive ,is to use Ti (Titanium )screws .
Titanium and aluminium won't pose galvanic corrosion issues .
But price of Ti screws are way high ...
alesh
Well-Known Member
I could get aluminum screws pretty well priced if I buy enough of them. Not much more expensive than stainless steel. But I've never used them. Would alu M3 be suitable for holders? Or M5 for the frame? Titanium is out of the way due to its price.
phaquetoo
Well-Known Member
my old 9 volt makita is the best and most powerful cordless drill I ever had, way better than the 16 volt craftsman, 18 volt ryobi, I wish I could get battery's for it!
Irwins are pretty good drill bits as a rule!
Peace
stardustsailor
Well-Known Member
Personally ,I wouldn't use them ...
Especially the M3 size ...
salmonetin
Well-Known Member
sds...and the nylon or pvc or poliamide screws?
Saludos
Saludos
whitebb2727
Well-Known Member
The risk of galvanic corrosion in a grow light is pretty low.
stardustsailor
Well-Known Member
Heat issues ...(material gets soft )
&
Not able to withstand high torque (which is needed in order to ensure high contact pressure )
(elastic polymers all of them )
Press "pause " and think it over ...
A grow space is a pretty humid environment ...
With plenty of corrosive gasses ...
( Nitrate & ammonium based fertilisers do emit NOx & NH3 gases ...
Same goes with Sulphur ferts .... SOx gassing out .
Things get worse when organic fertilisers are used ,
as the microfauna and microflora activity results in excessive gassing ...)
Also ,depending on the actual aluminium alloy used for the heat sink ,
galvanic corrosion could be a serious issue in a grow light ....
Exposed aluminium does form a protective layer of Al oxide ...
But ...
Threads are very prone to galvanic corrosion ..
Al2O3 protective layer gets grinded by the screw threads ,not exposed to air ,with humidity trapped inside ...
..Ideal environment for galvanic corrosion ...
Now press "play " again ...
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Fastslappy
Well-Known Member
I understand your concern but really what's the worst that would happen the screw seizes in the sink?
and how long would that actually take in a tent ?
I could see the concern if we working on airplanes & boats
my room evacuates the air @ a good clip & humity is always low to med never high
I run cheap ass Mars 2 years in there with steel screws in the lowest quality AL sinks
I tore down the mars for parts , no corrosion at all lotta dust
just sayin
and how long would that actually take in a tent ?
I could see the concern if we working on airplanes & boats
my room evacuates the air @ a good clip & humity is always low to med never high
I run cheap ass Mars 2 years in there with steel screws in the lowest quality AL sinks
I tore down the mars for parts , no corrosion at all lotta dust
just sayin
stardustsailor
Well-Known Member
Galvanic corrosion maybe more common in aerospace & marine environments ...I understand your concern but really what's the worst that would happen the screw seizes in the sink?
and how long would that actually take in a tent ?
I could see the concern if we working on airplanes & boats
my room evacuates the air @ a good clip & humity is always low to med never high
I run cheap ass Mars 2 years in there with steel screws in the lowest quality AL sinks
I tore down the mars for parts , no corrosion at all lotta dust
just sayin
Still it can be very easily present in a grow light ,too .
And you won't be able to notice it very easy ...
It usually forms inside the threads ,making the screws go loose ,
with the aid of thermal expansion/contraction .
personally ,I wont take the risk for my lights .
Neither I would buy lights that they have "tiny " (? ) faults like that ...
Since I'm a fuckin' perfectionist ,I never leave anything to luck ...
I want my lights to be 'state of the art '...
Of course the rest of you ,have every right to do as you wish with your lights .
Not my business,really.
I just note down all the worst possibilities .
And myself ,always trying to tackle or deal with 'em ...
Shit happens .
A basic rule of universe ...
And most of us tend to forget about or overlook it ...
Cheers.
whitebb2727
Well-Known Member
I don't need to press pause. I was a structural mechanic and corrosion control in the military. I wouldn't be worried about galvanic corrosion in a grow light. Galvanic corrosion is more of a problem with sea water and structures that sit in weather and get wet a lot. Soaking wet. There will be enough warmth from the cob to drive moisture from the threads.
stardustsailor
Well-Known Member
Here,in Greece ,usually amongst the bikers ,Titanium is also called Putanium .
From the italian word putana .
( Putana means prostitute )
It's called Putanium ,'cause one has to become a prostitute in order to buy Ti screws or parts ...
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