Model Boat Mayhem

Mess Deck: General Section => Beginners start here...! => Topic started by: rich_morris on May 07, 2020, 06:23:19 am

Title: Laser cut edges
Post by: rich_morris on May 07, 2020, 06:23:19 am
Hi,


It's a bit late now, as I've already bonded frames, keel and s couple stringers, but...


How necessary is it to remove/sand back to clean wood the laser  cutcut edges of ply wood?






So far I've only given them a quick rub with glass paper to remove any loose dust, and rough spots where the parts remained attached to the blank.


Rich




Title: Re: Laser cut edges
Post by: Martin (Admin) on May 07, 2020, 06:37:54 am
 
"a quick rub with glass paper"

Yeah, that's what I do.
You have to be careful, as the kits are cut exactly to size so and sanding will make for a sloppy fit.  {:-{
Title: Re: Laser cut edges
Post by: Barry on May 07, 2020, 09:48:36 am
Try wiping/rubbing the blacken edges with  methylated spirits.
Title: Re: Laser cut edges
Post by: JimG on May 07, 2020, 10:03:39 am
The amount of cleaning depends on whether they have used too much laser power or not. Good cutting leaves the edges a light brown colour needing only a light clean. Too much power leaves the edges blackened and needs more sanding to remove the charred wood. Leaving the char on reduces the strength of a glue join as the glue cannot soak into the wood so the bond is purely on the surface.
Jim
Title: Re: Laser cut edges
Post by: rich_morris on May 07, 2020, 10:06:17 am

"a quick rub with glass paper"

Yeah, that's what I do.
You have to be careful, as the kits are cut exactly to size so and sanding will make for a sloppy fit.  {:-{



Thanks, I'll keep doing that then. Or at least my son will keep doing that!
Title: Re: Laser cut edges
Post by: rich_morris on May 07, 2020, 10:07:44 am
Try wiping/rubbing the blacken edges with  methylated spirits.


Thanks, I'll give that a try.
Title: Re: Laser cut edges
Post by: rich_morris on May 07, 2020, 10:12:34 am
The amount of cleaning depends on whether they have used too much laser power or not. Good cutting leaves the edges a light brown colour needing only a light clean. Too much power leaves the edges blackened and needs more sanding to remove the charred wood. Leaving the char on reduces the strength of a glue join as the glue cannot soak into the wood so the bond is purely on the surface.
Jim


The edges don't seem too badly burnt. Certainly the brown doesn't rub off easily, even with sandpaper.
Edges are brown rather than black.
I'll keep giving them a light clean, unless they look overly burnt.
Thanks
Rich