Official Luthiers Forum!

Owned and operated by Lance Kragenbrink
It is currently Fri Nov 29, 2024 10:29 pm


All times are UTC - 5 hours


Forum rules


Be nice, no cussin and enjoy!




Post new topic Reply to topic  [ 13 posts ] 
Author Message
PostPosted: Fri Jun 14, 2019 6:04 pm 
Offline
Koa
Koa

Joined: Fri Feb 24, 2017 8:43 am
Posts: 1707
So do I need to respray this w a few coats???
Looks like I got a sand through that I didn’t notice until I buffed it
Still learning
Image


Sent from my iPhone using Tapatalk


Top
 Profile  
 
PostPosted: Fri Jun 14, 2019 6:14 pm 
Offline
Brazilian Rosewood
Brazilian Rosewood

Joined: Wed Feb 20, 2008 7:15 pm
Posts: 7380
First name: Ed
Last Name: Bond
City: Vancouver
Country: Canada
Focus: Build
Status: Professional
Fraid so...



These users thanked the author meddlingfool for the post: SnowManSnow (Fri Jun 14, 2019 6:34 pm)
Top
 Profile  
 
PostPosted: Fri Jun 14, 2019 6:35 pm 
Offline
Koa
Koa

Joined: Fri Feb 24, 2017 8:43 am
Posts: 1707
All good. Just another few weeks to cure . No hurry :)
Peace
Thanks Ed


Sent from my iPhone using Tapatalk


Top
 Profile  
 
PostPosted: Fri Jun 14, 2019 6:55 pm 
Offline
Koa
Koa

Joined: Fri Feb 24, 2017 8:43 am
Posts: 1707
The good part is the rest turned out like this:)
Image
Just have to have things done by Christmas is all so no rush.


Sent from my iPhone using Tapatalk


Top
 Profile  
 
PostPosted: Fri Jun 14, 2019 7:11 pm 
Offline
Contributing Member
Contributing Member

Joined: Sun Feb 17, 2013 4:58 pm
Posts: 1449
First name: Ed
Last Name: Minch
City: Chestertown
State: MD
Zip/Postal Code: 21620
Country: United States
Focus: Build
Status: Amateur
Snow

Looks like you may have unintentionally rounded over the edges a little. Be sure to use a sanding block of of some sort and don't let it go out over the edges when sanding. Nice finish on the body.

Ed



These users thanked the author Ruby50 for the post: SnowManSnow (Fri Jun 14, 2019 7:14 pm)
Top
 Profile  
 
PostPosted: Fri Jun 14, 2019 7:14 pm 
Offline
Koa
Koa

Joined: Fri Feb 24, 2017 8:43 am
Posts: 1707
Ruby50 wrote:
Snow

Looks like you may have unintentionally rounded over the edges a little. Be sure to use a sanding block of of some sort and don't let it go out over the edges when sanding. Nice finish on the body.

Ed

You’re right.


Sent from my iPhone using Tapatalk


Top
 Profile  
 
PostPosted: Fri Jun 14, 2019 10:53 pm 
Offline
Contributing Member
Contributing Member
User avatar

Joined: Mon Apr 16, 2012 12:47 pm
Posts: 2523
First name: Jay
Last Name: De Rocher
City: Bothell
State: Washington
I've sanded through on headstocks more than once. Hate it when that happens. One tip I'm pretty sure I picked up from this forum is instead of wrapping sandpaper around a sanding block, cut a piece of sandpaper the size of the sanding face of the block and double stick tape it to the block. The reason is that wrapping the sandpaper around the edge of the block causes the sandpaper to curve out slightly from the block where it wraps around the edge. It's not much but it's enough to cause more aggressive sanding at the edge of the block which is a problem as the edge of the block approaches the edge or corners of a small surface like the headstock. With the sandpaper double stick taped to the face of the block and not wrapping over the edges of the block, the sandpaper is flat all the way across the surface and you are less likely to sand through. Once I started doing that, the sand throughs stopped happening. This assumes that the wood surface is actually flat all the way across.

_________________
Once in a while you get shown the light in the strangest of places if you look at it right - Robert Hunter



These users thanked the author J De Rocher for the post: SnowManSnow (Fri Jun 14, 2019 11:33 pm)
Top
 Profile  
 
PostPosted: Sat Jun 15, 2019 4:48 am 
Offline
Koa
Koa
User avatar

Joined: Sat Jan 19, 2013 7:33 am
Posts: 1876
First name: Willard
Last Name: Guthrie
City: Cumberland
State: Maryland 21502
Zip/Postal Code: 21502
Country: United State
Focus: Repair
Status: Semi-pro
My natural tendency is to place far too much pressure on the edges, so early on in my training as a professional sander of wood and finishes (aka, luthier), I got three pieces of guidance:

- Stay off the edges

- No really - stay off the edges!

- You know, that wouldn't happen if you'd stay off the edges

But seriously, the techniques I learned focused on minimizing edge sand through and buffer burn through by doing the following:

- Properly prepare the surface before filling by rounding the arrises of the peghead sightly - this allows both a more uniform coating thickness on the edges (most coatings behave differently on edges than on flat surfaces, with lacquer flowing away from sharp edges, resulting in thinner film thickness there), and that slight radius spreads any applied sanding block pressure over a larger area.

- Unless a very conscious effort is used to reduce pressure on the block when operating over an edge, sanding pressure on the surface goes up as the area of the block in contact with the surface is reduced. Use a circular or oval sanding pattern on film-forming finishes like lacquer or waterbased polyurethanes or acrylics...besides eliminating the sort of deep, parallel scratches that are difficult to deal with when moving to the next finer grit, this sanding pattern keeps the pressure on the block more uniform and allows more of the block to stay registered on the surface (thus, avoiding excessive thinning of the finish film at the edges).

- Keep the pressure on the block inside the edge - this keeps the block flat and registered on the surface, versus following the edge and applying excess sanding pressure at the arrises.

- Avoid the issue noted above by Mr. De Rocher by using sanding blocks with a thick applied cork face and edges rounded or at the very least treated with a deep chamfer, then eased with the sander. This is more easily done with a cork face than wood, and the cork surface is more easily flattened after the first wet use on lacquer or oil varnish. This also encourages the sort of frequent paper changes needed when dry sanding water-based finishes and avoids the need to deal with double-stick tape or PSA when changing worn paper for fresh.

Attachment:
SandingBlocks.jpg


- Wet/dry papers to be used wet on lacquer or varnish should be soaked at least overnight - it softens the paper, allowing it to better conform to the block, as well as making the paper much easier to clear. We have 15-20 pieces each of 400, 800, and 1200 3M Imperial that live in plastic tubs ready for use, with a drop or two of Dawn detergent to discourage slime formation.

- Buff off the edge, keeping any pressure applied inside the edge, just as sanding pressure applied is kept inside the edges


You do not have the required permissions to view the files attached to this post.

_________________
For the times they are a changin'

- Bob Dylan



These users thanked the author Woodie G for the post (total 2): TimAllen (Tue Jun 18, 2019 1:10 am) • SnowManSnow (Sat Jun 15, 2019 8:46 am)
Top
 Profile  
 
PostPosted: Sat Jun 15, 2019 8:46 am 
Offline
Koa
Koa

Joined: Fri Feb 24, 2017 8:43 am
Posts: 1707
Scuffing and respraying this morning


Sent from my iPhone using Tapatalk


Top
 Profile  
 
PostPosted: Sun Jun 16, 2019 3:25 pm 
Offline
Koa
Koa

Joined: Fri Feb 10, 2017 11:09 pm
Posts: 870
Location: Cowichan Valley, BC, Canada
First name: Conor
Last Name: Searl
City: Duncan
State: British Columbia
Zip/Postal Code: V9L 2E5
Country: Canada
Status: Semi-pro
Woodie G wrote:
- Keep the pressure on the block inside the edge - this keeps the block flat and registered on the surface, versus following the edge and applying excess sanding pressure at the arrises.


What are arrises?


Top
 Profile  
 
PostPosted: Sun Jun 16, 2019 5:57 pm 
Offline
Koa
Koa
User avatar

Joined: Sat Jan 19, 2013 7:33 am
Posts: 1876
First name: Willard
Last Name: Guthrie
City: Cumberland
State: Maryland 21502
Zip/Postal Code: 21502
Country: United State
Focus: Repair
Status: Semi-pro
The sharp edge or salient angle formed by the meeting of two surfaces.

_________________
For the times they are a changin'

- Bob Dylan



These users thanked the author Woodie G for the post: Conor_Searl (Sun Jun 16, 2019 5:58 pm)
Top
 Profile  
 
PostPosted: Sun Jun 16, 2019 6:44 pm 
Offline
Contributing Member
Contributing Member

Joined: Sun Feb 17, 2013 4:58 pm
Posts: 1449
First name: Ed
Last Name: Minch
City: Chestertown
State: MD
Zip/Postal Code: 21620
Country: United States
Focus: Build
Status: Amateur
A table top with a square edge has an arris at the top/edge corner and at the bottom/edge corner. Your chisels have arrises (arissi?) at the sides where the edges meet the face and the back.

Ed



These users thanked the author Ruby50 for the post: Conor_Searl (Mon Jun 17, 2019 12:03 am)
Top
 Profile  
 
PostPosted: Mon Jun 17, 2019 12:03 am 
Offline
Contributing Member
Contributing Member
User avatar

Joined: Mon Apr 16, 2012 12:47 pm
Posts: 2523
First name: Jay
Last Name: De Rocher
City: Bothell
State: Washington
Oh boy, a new word! Can hardly wait to use it in a sentence. I'll have to be careful not to mix it up with arse.

_________________
Once in a while you get shown the light in the strangest of places if you look at it right - Robert Hunter


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 13 posts ] 

All times are UTC - 5 hours


Who is online

Users browsing this forum: Jim Watts and 43 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Jump to:  
cron
Powered by phpBB® Forum Software © phpBB Group
phpBB customization services by 2by2host.com