Easy fix for warped PBT spacebars


#1

This is a very simple fix that works quickly & permanently. You’ll need 3 tools for this.

  1. An aluminium speed square
    109060
  2. A heat gun
  3. A uniformly flat surface that can hold up to the heat from the heat gun

Step 1) Take the wide end of the speed square (the part meant to hook onto the piece being marked) & use it press the spacebar flat on your working surface.

Step 2) While using the speed square to hold down & flatten the warp out of the spacebar start blowing the hot air from the heat gun onto the exposed sides of the spacebar. Be sure to keep just enough pressure holding down to flatten out the warp throughout the heating.

Step 3) Once you have sufficiently heated the spacebar (it doesn’t take much I wouldn’t hit it with the heat gun for more than 30 sec.) shut the heat gun down, but continue to keep downward pressure on the spacebar until it has cooled sufficiently (about 1 1/2 to 2 min should be enough time). This is a very important step as letting the pressure of too early will result in the spacebar re-warping.

Step 4) Enjoy using a straight PBT spacebar!

While this is a pretty straight forward & common sense fix I figured I’d post it since I used this method to successfully fix a few spacebars from my PBT sets today. As long as you’re careful not to put too much downward pressure on the spacebar when heating & careful to not overheat it, this is a surefire way to quickly get any bad warps out of PBT spacebars!


#2

Been using my wife’s hairdryer and bare hands to do this. Was 50/50 on if I could hold on long enough to fix or if I’d bail out because it started to hurt quite a bit.

Will definitely look at a speed square in the future.

In short… keep your knuckle hair. Use a speed square.


#3

LOL, that last line cracked me up! I was gonna try a hair dryer at first but wasn’t sure it would put out enough heat. I just happened to have my speed square lying in the house from when I cut up some sorbathane & that’s what planted the seed of using it & a heat gun.


#4

Hey, thanks for sharing your method.

I too have a heat gun. Which temperature should I set it to before applying the heat to the PBT? It goes from 50 to 500 Celsius, aprox.


#5

No problem! I used mine at full tilt which is 565C, but like I said I only heated it for about 30 to 40 seconds after letting the gun warm slightly so it was probably running around 350C realistically. The ideal was to hopefully shock it into position with a rapid heating & cooling, not sure how much difference a longer heating &/or cooling time would affect the process. I also held the nozzle about 15" away & was constantly moving the gun in a circular path around the outside of the spacebar. PBT melts at 223c & is fairly heat resistant up to 150C so you’d have to really overheat it bad to mess the cap up in anyway.


#6

This is a smart method - but I stand by my method of “almost-boiling water and an aluminum NIU mini” to straighten it out. Works wonders!


#7

nice tips! - the speed square looks like a good way to deal w/ the heat. When I had lukewarm success w/ a hairdryer, I ended up burning my fingers or having the hairdryer blow away the key lol!


#8

You are onto to something with almost boiling water. When I was checking out the properties of PBT I found out that in open air it is very heat resistant, but in water it’s heat resistance drops pretty significantly.


#9

So… having no speed square at hand, I decided to try out my luck by first heating the spacebar with the heat gun set at maximum temperature, only for around 40 seconds. Immediately afterwards, I put a heavy book on top of my spacebar, and let it sit there for quite a few minutes (around 20).

It didn’t work. :disappointed: Spacebar remains warped and, what’s even worse, it now rubs against the wall of my high-profile case (a Klippe+) when I press it down. Looks like it got expanded by the heat along the “y” axis. I guess I’ll try to source a speed square, and try again.


#10

I took a flat-bottom bowl and got some water going in my Keurig, and that did the job quite nicely.


#11

Damn, sorry to hear that man. I think it is pretty important to keep the spacebar forced into the the position you want all the way through heating & cooling it. I also didn’t have any expansion of my spacebars I did this to, I think you may have overheated it a bit. Maybe give @Lesbian’s way of using hot water a try to get the horizontal warp out.


#12

I tried to fix a 7u DSA spacebar a year or so ago with a hairdryer. Got it perfectly flat. It no longer worked correctly on the stabilizers. So I guess SP manufactures knowing it will curve slightly and have the correct stem to stem measurement when slightly warped? I don’t try to flatten them anymore :frowning:


#13

I have a space bar that isn’t warped but it seems as if one of the posts for my 7u spacebars is barely wider than it needs to be. It makes my stabilizers have more resistance and scratch… Maybe I will try this and see if it fixes it.