getting perfect joints by filling gaps? - Woodworking Talk - Woodworkers Forum
 3Likes
  • 1 Post By hawkeye10
  • 1 Post By hawkeye10
  • 1 Post By Quickstep
 
Thread Tools Display Modes
post #1 of 16 Old 06-27-2018, 05:20 AM Thread Starter
Member
 
Join Date: May 2018
Posts: 73
View Tom Lilletveit's Photo Album My Photos
getting perfect joints by filling gaps?

I am building a guitar and in some areas I want the best possible fit between two parts of wood to wood or wood to metal.

Working with a straight edge and being carefull I am able to get stuff to fit pretty nicely but tiny gaps like 0.02mm-0.6mm can be very difficult to fix by sanding, especially in areas where there are slight curves and angles.

I could glue it, but in some cases I do not want the two surfaces to stick to eachter as they are screwed fast, and i want to be able to remove the part easily.

So i want something that becomes hard and sticks to the wood, but not the metal plate. Like some glue I could get in between the cracks when the two parts are joined together, and then when it hardens not having the two part stick to eachother.


I was thinking maybe using something like hide glue, spray something like bicycle oil on the metal part then clamp the two pieces together and wait for the hide glue to stiffen then remove the part. However I do not know how hard hide glue gets, or if its suited for this purpose.


Any recommendations?
Tom Lilletveit is offline  
Sponsored Links
Advertisement
 
post #2 of 16 Old 06-27-2018, 07:13 AM
Senior Member
 
hawkeye10's Avatar
 
Join Date: Feb 2015
Location: Murfreesboro, Tn.
Posts: 1,107
View hawkeye10's Photo Album My Photos
I don't build guitars but maybe I can help you out with part of your problem. I do know glue or epoxy will not stick to wax. I used to bed rifle actions and I used shoe polish so the epoxy would not stick to the rifle action. One of the Moderators here builds guitars and if he would get up out of the bed he could help you. His name is David. I just don't know what is going on with these young folks. They want to stay in bed all day.

PS- He is a good guy and knows I am kidding.
difalkner likes this.

Don in Murfreesboro, TN.

Last edited by hawkeye10; 06-27-2018 at 07:18 AM.
hawkeye10 is offline  
post #3 of 16 Old 06-27-2018, 08:07 AM Thread Starter
Member
 
Join Date: May 2018
Posts: 73
View Tom Lilletveit's Photo Album My Photos
Quote:
Originally Posted by hawkeye10 View Post
I don't build guitars but maybe I can help you out with part of your problem. I do know glue or epoxy will not stick to wax. I used to bed rifle actions and I used shoe polish so the epoxy would not stick to the rifle action. One of the Moderators here builds guitars and if he would get up out of the bed he could help you. His name is David. I just don't know what is going on with these young folks. They want to stay in bed all day.

PS- He is a good guy and knows I am kidding.



I want a material that transfer vibrations well, so something that gets hard. I think epoxy is pretty much hatet by most luthiers, dont know if thats cause of what it does to the tone or cause it is difficult to repair a guitar where epoxy is used. For my purposes I cant see that epoxy would make the guitar any more difficult to repair since i am not bonding two surfaces. What epoxy does to the tone I have no idea about, people who knows this stuff is very rare and tend to shy away from daylight.

Last edited by Tom Lilletveit; 06-27-2018 at 08:10 AM.
Tom Lilletveit is offline  
Sponsored Links
Advertisement
 
post #4 of 16 Old 06-27-2018, 09:25 AM
johnep
 
Join Date: Apr 2007
Location: East Anglia UK
Posts: 1,897
View johnep's Photo Album My Photos
I would use a piece of polythene to separate the metal and glue.Once glue set, remove the polythene. Me, I would use Plastic padding or car filler.
johnep
johnep is offline  
post #5 of 16 Old 06-27-2018, 09:33 AM
Senior Member
 
Join Date: Sep 2011
Posts: 25,991
View Steve Neul's Photo Album My Photos
Depending on the stress put on the part I think .6 mm is within tolerable limits when using wood glue. A lot of times when wood is that close to fitting you can use clamps to force it the rest of the way. It shouldn't take very much pressure. Wood glue would slightly stick to the metal but wouldn't actually make a bond. It works by soaking into the wood fibers and metal isn't porous. If you don't want any adhesion to the metal at all then put a piece of package sealing tape on the metal. Then after the wood has been glued remove the metal and peal the tape off. Using oil around wood is a bad idea. If it gets on the wood it could stain the wood and if you plan on a varnish type finish the oil can cause adhesion problems.
Steve Neul is offline  
post #6 of 16 Old 06-27-2018, 09:52 AM Thread Starter
Member
 
Join Date: May 2018
Posts: 73
View Tom Lilletveit's Photo Album My Photos
Quote:
Originally Posted by johnep1934 View Post
I would use a piece of polythene to separate the metal and glue.Once glue set, remove the polythene. Me, I would use Plastic padding or car filler.
johnep

Thats a good idea, i think the thinnes plastic I have available is some food grade cling film
Tom Lilletveit is offline  
post #7 of 16 Old 06-27-2018, 09:55 AM Thread Starter
Member
 
Join Date: May 2018
Posts: 73
View Tom Lilletveit's Photo Album My Photos
Quote:
Originally Posted by Steve Neul View Post
Depending on the stress put on the part I think .6 mm is within tolerable limits when using wood glue. A lot of times when wood is that close to fitting you can use clamps to force it the rest of the way. It shouldn't take very much pressure. Wood glue would slightly stick to the metal but wouldn't actually make a bond. It works by soaking into the wood fibers and metal isn't porous. If you don't want any adhesion to the metal at all then put a piece of package sealing tape on the metal. Then after the wood has been glued remove the metal and peal the tape off. Using oil around wood is a bad idea. If it gets on the wood it could stain the wood and if you plan on a varnish type finish the oil can cause adhesion problems.

I agree, untreated wood is really hard and in some cases impossible to clean up if you have stained it by mistake. I've already done it so I should know.
Tom Lilletveit is offline  
post #8 of 16 Old 06-27-2018, 10:37 AM Thread Starter
Member
 
Join Date: May 2018
Posts: 73
View Tom Lilletveit's Photo Album My Photos
I've done some searching and both epoxy and hide glue can be used as a structural glue to fill gaps, wood glue is not so good since it does not harden like the other two.



Ill try with hide glue as it is easy to remove if ill have problems later on.
Tom Lilletveit is offline  
post #9 of 16 Old 06-27-2018, 11:05 AM
Wood machinist
 
difalkner's Avatar
 
Join Date: Nov 2011
Location: NW Louisiana
Posts: 3,636
View difalkner's Photo Album My Photos
Sorry for the delay in responding, just got out of bed...

Use a piece of parchment paper, Tom. When the glue is fully cured the parchment paper will just peel right off and allow the two parts to be separated when needed, assuming I'm understanding what you're wanting to do.

David

David

Curly Wood Shop on Etsy
David Falkner - Woodworking YouTube channel
Our music at church - current videos Airline Baptist BC Facebook Live
Romans 3:23
difalkner is offline  
post #10 of 16 Old 06-27-2018, 12:23 PM
Senior Member
 
hawkeye10's Avatar
 
Join Date: Feb 2015
Location: Murfreesboro, Tn.
Posts: 1,107
View hawkeye10's Photo Album My Photos
Quote:
Originally Posted by difalkner View Post
Sorry for the delay in responding, just got out of bed...

Use a piece of parchment paper, Tom. When the glue is fully cured the parchment paper will just peel right off and allow the two parts to be separated when needed, assuming I'm understanding what you're wanting to do.

David
David, you brought up using parchment paper reminds me that some people used Suran Wrap to keep epoxy from sticking to the actions on rifles. I would also put painters tape on the outside of a rifle stock to keep epoxy squeezeout from getting on the stock. All of this stuff will work. You just have to figure out what you want to do.
difalkner likes this.

Don in Murfreesboro, TN.
hawkeye10 is offline  
post #11 of 16 Old 06-27-2018, 02:55 PM
Senior Member
 
Join Date: Feb 2018
Posts: 132
View pro70z28's Photo Album My Photos
You could spray or brush the metal parts with a release agent. Used on fiberglass molds to allow parts to be pulled once the fiberglass has cured, and can be purchased wherever fiberglass materials are sold. Dries super thin and won't move around or bunch up like paper or plastic might. Wash off when done.
pro70z28 is offline  
post #12 of 16 Old 06-27-2018, 09:47 PM
Senior Member
 
Join Date: Apr 2012
Posts: 2,619
View Quickstep's Photo Album My Photos
What parts are you gluing? Knowing that might help us understand what youíre up against.

Hatred of Epoxy by luthiers is somewhat unfounded. Epoxy joints can absolutely be reversed, theyíre just harder to clean up afterward.
For joints youíre unlikely to need to take apart anyway, Epoxy has some advantages. For example, since Epoxy contains no water, it wonít distort the neck when gluing a fingerboard and I know luthiers that use Epoxy for fingetboards for just that reason. For braces, Epoxy is probably a no-go.

In addition to WWTalk, Iím also on a luthiers forum with some knowledgeable folks who are very generous with their knowledge, some of whom are famous luthiers.

https://www.acousticguitarforum.com/...splay.php?f=44
difalkner likes this.
Quickstep is offline  
post #13 of 16 Old 06-29-2018, 08:48 AM Thread Starter
Member
 
Join Date: May 2018
Posts: 73
View Tom Lilletveit's Photo Album My Photos
I did not have much sucess with hide glue and plastic film, did not close the gaps, and I think it will require quite a bit trial and error and tinkering to close 1/10 of a mm gaps. Plan B is to simply actually glue the pieces together with hide glue, If I have to remove them at some point, which I doubt. It should come off easily anyways just by applying heat to the metal part.


Its the metal part in the picture bellow I am fastening. The strings provide quite a big of pull tension so I want it seated tight. Actually when i bought this thing it came with two 2mm thick 1.8cm long screws. Hah! I believe it would tear right off once I stringed the guitar using those tiny screws. I replaced them with some m3.5 3cm ones
Attached Thumbnails
Click image for larger version

Name:	steinberger-spirit-gt-pro-deluxe-white-506988.jpg
Views:	39
Size:	61.6 KB
ID:	363228  


Last edited by Tom Lilletveit; 06-29-2018 at 08:57 AM.
Tom Lilletveit is offline  
post #14 of 16 Old 06-29-2018, 09:06 AM
Wood machinist
 
difalkner's Avatar
 
Join Date: Nov 2011
Location: NW Louisiana
Posts: 3,636
View difalkner's Photo Album My Photos
Where is the gap on yours, Tom? Can you post a photo?

David

David

Curly Wood Shop on Etsy
David Falkner - Woodworking YouTube channel
Our music at church - current videos Airline Baptist BC Facebook Live
Romans 3:23
difalkner is offline  
post #15 of 16 Old 06-29-2018, 07:40 PM
Senior Member
 
Join Date: Apr 2012
Posts: 2,619
View Quickstep's Photo Album My Photos
Sorry if I'm being dense, but I don't see a gap.
Quickstep is offline  
post #16 of 16 Old 06-29-2018, 08:59 PM
Wood machinist
 
difalkner's Avatar
 
Join Date: Nov 2011
Location: NW Louisiana
Posts: 3,636
View difalkner's Photo Album My Photos
I think that's a stock photo from the Steinberger website.

David

David

Curly Wood Shop on Etsy
David Falkner - Woodworking YouTube channel
Our music at church - current videos Airline Baptist BC Facebook Live
Romans 3:23
difalkner is offline  
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Woodworking Talk - Woodworkers Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Similar Threads
Thread Thread Starter Forum Replies Last Post
Recommendations for filling gaps in table top jgallow26 Wood Finishing 5 01-16-2018 05:46 PM
Need advice on failed glue joints [email protected] General Woodworking Discussion 4 10-29-2017 01:58 AM
what kind of joints are these? norcaljoey Joinery 9 09-20-2016 10:13 AM
recommended method for creating box and other wood joints jrcharvey Power Tools & Machinery 3 12-28-2015 12:28 AM

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

 
For the best viewing experience please update your browser to Google Chrome