Avoiding Router Burn

[Mickguard]

I'm getting closer to the final body size --I want to make another pass with the collar/bit combination (that'll leave about 1 mm) before I use the template bit for the final shape.

I'm hoping to get tips on how to avoid router burn?

I'll be using a high quality carbide bit for the next pass and a pro-quality template bit. So I'm guessing that will help a lot (I've been using up the cheap bits that came with the router for the rough shaping work).

I'm getting pretty good at using a light touch with the router, guiding it rather than digging it in. I'm doing very light passes --it actually feels more like I'm shaving the wood than anything else. Takes longer I suppose but no tearouts so far!

The template bit is longer than the sides of the blank--so when I get to it, I plan on going for the entire side at once (because there'll only be 1 mm to get through).

But other than good bits and a light touch --what else should I be looking at to keep from burning the sides?

[RGGR]

Burning is caused by friction.......when router bit cuts....it just does this very efficient. Leave bit too long in same area....and due to friction burn marks appear.

So keep the bit (or piece of wood, depending on set-up) moving at all times.

[Doc]

Also if your bit bogs down because you're asking the router to do more than it can you'll burn. Keep using the light passes and you'll be okay.

Keep the bit clean. When pitch builds up at all it heats up the bit and dulls the edge.Get some of the commercial bit and blade cleaner. Don't use the cheap alternatives that someone here is sure to recommend. Oven cleaner is expecially bad.It weakens the braze that holds the carbide on. Learned that the hard way.

I use Boesheild spray lubricant. I think it's called T-9. It doesn't react with finish and it gives me about three times the life of an untreated bit.

[Daniel Sorbera]

Also if you have a variable speed router you might have it to high. I found that having it set to fast will burn really bad. Maple espicially.

[tirapop]

I've used Dri-Cote, a spray on bit lubricant. It works. Blades and bits pick up less pitch, stay cooler, and burn less.

[thegarehanman]

does it have silicone or anything else that would inhibit the application of a finish coat in it?

Edited September 30, 2005 by thegarehanman

[unclej]

one of the best ways to avoid router burn even with older bits is to make several passes. let's say that you're routing a round over all around the perimeter of your guitar body. don't lower your bit to the final depth. start with it a little higer, say half the final depth, make a run around the guitar and then lower it to your final setting. the bit is taking less material with each pass so it's not working as hard and is much less likely to burn.

also make sure that your bearing is spinning freely and kept lubricated. a dragging bearing can burn the wood even though the blade itself might not be.

[Mickguard]

Cool...thanks for the tips.

I didn't know you were supposed to clean your bits!

[kench]

Remember that "HEAT IS YOUR BIT'S WORST ENEMY". You can easily blunt your bits if you use it with higher speed than needed. Just because of the heat, not the hardness of your wood. Use the slowest-possible setting on your router, due to your bit's size. 20000 - 25000 rmp is only for the bits with around 6 mm cutting diameter. For wider bits, you must use slower settings.

I ruined a 12 mm bit with only routing neck pocket on mahogany because I was using a 27000 rmp router!!!

[Mickguard]

Okay, thanks for the tips -- I slowed the router down to about 2.5 (it goes to 6)....I also made fairly shallow passes and kept the router moving smoothly all the while...

Got pretty good results --the only place I had trouble was around the tips of the horns, but that came especially from not having a stable base for the router, so I couldn't keep the router moving as smoothly as I'd want.

I forget who posted the suggestion to cut a square MDF 'table' to go around the guitar --it was in another thread-- but it's a great idea, I'm going to put together something like that for the final route.

[Mickguard]

A follow up...just finished shape most of the body (there's a section that has to wait for later)...

Thanks to everyone's tips it came out great --no tearouts, no burn!

Thanks!