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-   -   Using an engraver (https://vansairforce.net/community/showthread.php?t=79959)

330Jock 12-12-2011 09:52 PM

Using an engraver
 
I just read a post about using an engraver to mark all the parts before priming so it will be readable after cleaning and priming. Isn't that a no no? I thought any scratches etc., could lead to stress cracks. Someone please hep me out here.
Bill

lorne green 12-12-2011 11:09 PM

My understanding is that using an engraver is OK. Magnifying the engraving shows a line of small indentations...the surface is not being scratched.
Take a look at QB wings. The wing root spars are engraved at the factory. Engraving an identifying code to the parts to be primed is a good idea.
It is a little tricky tying to i-dent the parts after the stickers are off.:)

marchudson 12-13-2011 04:35 AM

Bill

Welcome to the forums.

Not saying that the engraving method is wrong or right but that it is a lot of extra work when a sharpie works just fine. I used a black sharpie and the ID was readable through the primer. If it isn't, maybe a little too much primer was being applied. Try it out on a scratch piece.

Hope this helps.

Got2Fly 12-13-2011 05:13 AM

I agree with using the sharpie. It works very well for me, and I tend to use it liberally. If' I'm match drilling holes and get interrupted, I mark where I left off so I don't miss any holes. When disassembling after match drilling, I use it to mark where parts go to make re-assembly easier.

flytoboat 12-13-2011 06:08 AM

Quote:

Originally Posted by 330Jock (Post 605322)
I just read a post about using an engraver to mark all the parts before priming so it will be readable after cleaning and priming. Isn't that a no no? I thought any scratches etc., could lead to stress cracks. Someone please hep me out here.
Bill

I am not close to my instructions to give you a reference, but Van's instructions does allow using a vibrating engraver.

RV7Ron 12-13-2011 07:46 AM

Quote:

Originally Posted by flytoboat (Post 605365)
I am not close to my instructions to give you a reference, but Van's instructions does allow using a vibrating engraver.

Agreed, Van's endorses it and the wing spars are engraved. I bought a cheap one from Harbor Freight and it works great, and frankly doesnt take any longer than using a sharpie since I keep it handy at the workbench. Personal preference...but its safe to do. And welcome!

330Jock 12-13-2011 08:08 AM

Thanks guys!
Bill

rv7charlie 12-13-2011 12:58 PM

Also, a sharpie will *not* survive the clean/acid etch/alodine process. Which is more work than primer, but according to those who have done real world testing in a salt water bath, will provide the same protection as epoxy primer with effectively unmeasurable increase in weight.

Charlie

Space Cadet 12-13-2011 01:09 PM

Solvent wipes
 
Sharpie also will not survive a good solvent wipe, which should be done before primer is applied. Or you have to apply twice- once when first building/assembling the part, then again right after wiping clean prior to priming.

Dwight

David Paule 12-13-2011 06:30 PM

Small card tags on strings work, too. Like a Sharpie, you need to remove it for cleaning or priming. Unlike Sharpies or engraving, you remove them before final assembly. And unlike engraving, there's no chance of harming the part.

The collection of used tags is a reference to what is finally assembled.

The downsides to these are that they can infrequently fall off, or get mutilated, and once they are off, there's no indication that the part has any identification.

Pros and cons - but at least there is a third approach to the issue.

Dave


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