trying to drill into my hs why do is it so hard

whitebb2727 said:

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.

Click to expand...

I used to work in Military Avionics industry..
Galvanic corrosion does take place in a grow light .
As also takes place in relatively dry environments ,with presence of electrolytes or ions from gasses.
It just needs more time ,than " sea water and structures that sit in weather and get wet a lot. Soaking wet."

How does moisture drives away from a " blind hole " ,
with a screw tightly tighten at the " open " end ?And a plastic COB case /holder over it ?
Anyway ..
I 've already mention : ": You have every right to do as you wish with your lights . "
As I 've with mine ...

stardustsailor said:

I used to work in Military Avionics industry..
Galvanic corrosion does take place in a grow light .
As also takes place in relatively dry ,ground environments ..
It just needs more time ,than " sea water and structures that sit in weather and get wet a lot. Soaking wet."

How does moisture drives away from a " blind hole " ,with a screw tightly tighten at the " open " end ?
Anyway ..
I 've already mention : ": You have every right to do as you wish with your lights . "
As I 've with mine ...

Click to expand...

The same way the moisture got in.

The truth is if you use steel or zinc plated screws and a drop of lock tite it will be fine.

I mean the way you talk about it you act like its going to happen quickly. The light will likely be obsolete before galvanic corrosion is an issue.

whitebb2727 said:

The same way the moisture got in.

The truth is if you use steel or zinc plated screws and a drop of lock tite it will be fine.

I mean the way you talk about it you act like its going to happen quickly. The light will likely be obsolete before galvanic corrosion is an issue.

Click to expand...

1) Moisture got in ,while washing the tapping lub & debris off ...

2) No,ain't gonna happen quickly ,as in aerospace or marine environment

3) Obsolete ? Depends on the light ...The lights I make won't be obsolete easy ...
Maybe after years new drivers and fan ,would replace the old ones ...
Same goes with the COBs ...
After years of operation ,one can replace them with the newest Vero 29 ..version 5 ..
The rest of the light remains the same .Heat sink included ...

I do not make "consumer grade " lights ...
I want my lights to be operational for at least 10-15 years ..
And when the tech advances ,only some parts will be replaced ..
Still the lights will be fully operational ...

Loctite is a very good idea ,though ...

Cheers.


P.S. : I do hate rusted screws ,also ...

stardustsailor said:

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 ...

Click to expand...

I see yer concern now & yes you should address it if your in salt water environment
IE;near crashing waves ,beaches , live on the water
i live near the SF bay 1/2 mile as the crow fly , but it's protected by the coastal range

So there's no Salt mist present in the air if you are in a area like the above
yes U should at least look at maybe a better screw
mostly important would be you Passive guys with the butTass big Expensive sinks
IF I dropped that coin into sinks like you have ,
Yes I'd address it , as I'm not perfectionist
But 'OverKill" is my middle name & my motto is 'More Is Better ! '

Lock tight seems like a bit of overkill to hold down some cobs... I've yet to have a cob screw wiggle lose on its own.

whitebb2727 said:

The light will likely be obsolete before galvanic corrosion is an issue.

Click to expand...

my point as well
i was in aircraft maint too .
we seen more corrosion inside holddowns on the passenger seats & floor boards than most anywhere else
that was the cleaning crew that causes that & spills of soda & the like
Boeing makes a anti seize for AL & they paint everything in green stuff & anodize
aircraft actually are flying boats , that's how they approach corrosion in design

bicit said:

Lock tight seems like a bit of overkill to hold down some cobs... I've yet to have a cob screw wiggle lose on its own.

Click to expand...

If screws untighten so much that " cob screw wiggle lose on its own " ,
then your COB is going -most probably- to be fried ...

Check your COB /holder screws every 6 months or so
and I bet that you will find some that are not tighten the way that used to be ...

Thermal expansion /contraction cycling ....

hey drilled all holes ..quick question on my hs do i have to sand and clean with alcohol ..i forgot will it make a diff and should i do so ..or is it just for looks

Fastslappy said:

I see yer concern now & yes you should address it if your in salt water environment
IE;near crashing waves ,beaches , live on the water
i live near the SF bay 1/2 mile as the crow fly , but it's protected by the coastal range

So there's no Salt mist present in the air if you are in a area like the above
yes U should at least look at maybe a better screw
mostly important would be you Passive guys with the butTass big Expensive sinks
IF I dropped that coin into sinks like you have ,
Yes I'd address it , as I'm not perfectionist
But 'OverKill" is my middle name & my motto is 'More Is Better ! '

Click to expand...

Take a glance of where I live ...

stardustsailor said:

Take a glance of where I live ...

View attachment 3595117
View attachment 3595119

Click to expand...

that is beautiful..

john0000 said:

that is beautiful..

Click to expand...

The whole country is beautiful ...
Other than that it's really a shithole to live ....
Only thing left in one piece , is natural beauty ...
Ok ..And food also ...

Yes , Nice !
That's That's the Salt rich sea environment I was describing
i'd act like I was making Pier lights ,
I figured you lived in a place like that ,
If I lived in the SF Sunset District (huge beach near & epic waves as well) I'd be more like your place
the bay goes lap lap near me on tidal flats lol

john0000 said:

hey drilled all holes ..quick question on my hs do i have to sand and clean with alcohol ..i forgot will it make a diff and should i do so ..or is it just for looks

Click to expand...

You can sand it to make it smooth ..
does not have to be mirror polished ,though ...
Test the flatness with a (old fashioned) razor blade ...

Yes,you will have to clean it with isopropyl alcohol ,before mounting the COBs..

Fastslappy said:

Yes , Nice !
That's That's the Salt rich sea environment I was describing
i'd act like I was making Pier lights ,
I figured you lived in a place like that ,
If I lived in the SF Sunset District (huge beach near & epic waves as well) I'd be more like your place
the bay goes lap lap near me on tidal flats lol

Click to expand...

Check out my favourite beach .Half an hour away from home ..Really small and isolated ...

Fastslappy said:

my point as well
i was in aircraft maint too .
we seen more corrosion inside holddowns on the passenger seats & floor boards than most anywhere else
that was the cleaning crew that causes that & spills of soda & the like
Boeing makes a anti seize for AL & they paint everything in green stuff & anodize
aircraft actually are flying boats , that's how they approach corrosion in design

Click to expand...

I worked on a couple different airframes. One was modified Boeing 707.

stardustsailor said:

You can sand it to make it smooth ..
does not have to be mirror polished ,though ...
Test the flatness with a (old fashioned) razor blade ...

Yes,you will have to clean it with isopropyl alcohol ,before mounting the COBs..



Check out my favourite beach .Half an hour away from home ..Really small and isolated ...
View attachment 3595131

View attachment 3595133

Click to expand...

What can you do if it isn't completely flat?

737 , FH227 & F27 we'd fly into bush villages in the Arctic, Bering Sea , Prudhoe Bay ,Deadhorse ,
they'd land a 737 on gravel & ice run ways
the 737's had a ski that kept rocks outta the engines & a boom off the engines' intake that blew a blast of engine exhaust downward to firther protect the engine

whitebb2727 said:

I worked on a couple different airframes. One was modified Boeing 707.

Click to expand...

J Bleezy said:

What can you do if it isn't completely flat?

Click to expand...

sand it ,until it's flat ...

For the US CAMI grit :
Start with 240- 360 to make it flat .
Use an orbital electric sander .
Avoid using a belt sander or random orbital sander ,
as they tend to take away too much material and are difficult to finely control ...
( Avoid to sand away too much material...Only the necessary ,until flatness is achieved )
Then sand with (wet ) 500-1000 for a smooth finish .

For EU ISO/FEFA grit :
Start with P280- P500 to make it flat .
Then sand with (wet ) P800-P2000 for a smooth finish .

https://en.wikipedia.org/wiki/Sandpaper
http://www.popularmechanics.com/home/tools/reviews/a3118/know-your-power-sanders-and-how-to-use-them-13314160/

stardustsailor said:

sand it ,until it's flat ...

For the US CAMI grit :
Start with 240- 360 to make it flat .
Use an orbital electric sander .
Avoid using a belt sander or random orbital sander ,
as they tend to take away too much material and are difficult to finely control ...
( Avoid to sand away too much material...Only the necessary ,until flatness is achieved )
Then sand with (wet ) 500-1000 for a smooth finish .

For EU ISO/FEFA grit :
Start with P280- P500 to make it flat .
Then sand with (wet ) P800-P2000 for a smooth finish .

https://en.wikipedia.org/wiki/Sandpaper
http://www.popularmechanics.com/home/tools/reviews/a3118/know-your-power-sanders-and-how-to-use-them-13314160/

Click to expand...

this needs to be sanded down then, correct? Looks like another thing to add to the shopping list lol
I appreciate the help!

J Bleezy said:

View attachment 3595163 this needs to be sanded down then, correct? Looks like another thing to add to the shopping list lol
I appreciate the help!

Click to expand...

Yes ,it needs a bit of flattening ..Not much though ...
Try to find a flat (but as flat as possible ) thing ,about the size of the COBs you want to install .
Check again with that .

Also @ john0000

Since you've finished drilling the holes ,
do not forget to smooth out the hole lips ,before sanding ...

You 've to do that ,so that the COB/holder will "sit " totally in contact with the heat sink ...

2 ways to do that :

1) Either with a razor or sharp knife ,take away (slice / cut lightly around the hole lip ) any "chips" remaining at the hole lip .

2) Lightly countersink the lip of the holes.Just lightly.
Use a drill bit double the size of the one you used to drill the hole .
( if you used 2.5 mm (for a M3 thread ) then use 5 mm for a light countersinking.
- I'm not familiar with the US drill sizes )

a ) Set the drill in motion,
b ) center it over the hole
and then c ) lightly touch the hole lip with the drill bit .

You do not want a full countersinking .
Just enough for the hole lips to be clean and smooth ,
without any "chips" from drilling .

whitebb2727 said:

I worked on a couple different airframes. One was modified Boeing 707.

Click to expand...

I do that by hand with a larger bit & just roll back & forth lightly
& then check for flatness do all this before sanding
& remember to clean the threads & all holes of dust after, between & before U work
sand paper leaves grit behind Keep Clean Really means it