LumberJocks

magnetic knife rack

  • Advertise with us

« back to Designing Woodworking Projects forum

Forum topic by willhime posted 09-11-2014 06:29 AM 1535 views 1 time favorited 9 replies Add to Favorites Watch
View willhime's profile

willhime

81 posts in 998 days


09-11-2014 06:29 AM

Topic tags/keywords: question tip trick

I’ve been losing the battle on getting this knife rack up to snuff over the past week. About $30 on rare earth magnets (supposedly the strongest readily available magnets there are), and the rack will just barely hold up a USMC Ka-bar knife. I used that knife as a model because the majority of households will usually have the big bulky german knives vs lighter japanese ones. Every tutorial I see online has the instructions to drill out or route out the back side leaving only 1/8” surface wood so the magnets can get as close as possible to the surface. After doing that so thin, I could see daylight through it when held up, the knife was still hanging on by a prayer. So next, I decided to surface mount all the magnets and put a piece of thin veneer (1/32”) over the ugly face to hide all the glue and of course magnets. I now have roughly 60 magnets on this 20” rack and it’s still not strong enough to my liking. Am I missing something? I have no idea what else to do…

-- Burn your fire for no witness


9 replies so far

View RRBOU's profile

RRBOU

136 posts in 1751 days


#1 posted 09-11-2014 09:42 AM

When it comes to magnets bigger is still more powerful. If you would have used larger diameter magnets you would have the results you are seeking.

-- If guns cause crime all of mine are defective Randy

View mtenterprises's profile

mtenterprises

933 posts in 2152 days


#2 posted 09-11-2014 11:00 AM

As I see from your picture how all your many magnets are mounted my question is. Are all the same poles facing in the same direction? You do know that one side of the magnet is north and the other south if they are mixed in which way they are facing the the strength is diminished. I know this from building a magnetic stud finder, all have to be facing the same way.

MIKE

-- See pictures on Flickr - http://www.flickr.com/photos/44216106@N07/ And visit my Facebook page - facebook.com/MTEnterprises

View ChefHDAN's profile

ChefHDAN

805 posts in 2309 days


#3 posted 09-11-2014 12:30 PM

I was curious so I just went and tested it, the 1” RA magnet in my magnetic featherboards can lift a 10# balanced weight. If you look at the design of the traditional mag bar used for knives the magnet is sandwiched by steel to make contact with the blade. Your design doesn’t have enough magnet force, especially with the veneer separation. Also, and it may be a visual photo trick, but it looks like some of your magnets are recessed below the surface of the wood, and/or tilted a bit in their holes, that coupled with the polarity question may be your issue. To try and use your investment of magnet so far, I’d start over and run a dado with router or TS and line up the magnets in a tighter pattern so that they would have more contact with the blade.

-- I've decided 1 mistake is really 2 opportunities to learn.. learn how to fix it... and learn how to not repeat it

View willhime's profile

willhime

81 posts in 998 days


#4 posted 09-11-2014 09:34 PM

salvaging the magnets would be preferable, but I don’t know if I can get them out (LocTite) without breaking them since they’re super brittle

-- Burn your fire for no witness

View Richard's profile

Richard

1897 posts in 2149 days


#5 posted 09-11-2014 09:49 PM

I would think that the magnets you use did not have the strength you need for a knife rack. These guys have some that are small enough to work for it have over a 20 pound hold strength, even if the wood cut it down by half that wouold still be 10 pounds and that should be good enough for kitchen knives.
http://www.kjmagnetics.com/products.asp?cat=10
DC6-N52 29.7 lb $6.39 ea.
3/4” dia. x 3/8” thick
Nickel Plated
Axially Magnetized

DX04B-N52 33.7 lb $7.70 ea.
1” dia. x 1/4” thick
Black Nickel Plated
Axially Magnetized

View hairy's profile

hairy

2384 posts in 2991 days


#6 posted 09-11-2014 10:18 PM

I went the simple route. It’s a magnetic bar attached to the fridge. These are made for tool organizing. The ones I have came from one of the tool trucks, Mac, Matco, SnapOn, I don’t remember.

It’s a T shaped housing, the magnets on each side are exposed. Harbor Freight sells a less costly version.

http://www.harborfreight.com/18-in-magnetic-tool-holder-61199.html

I have some of the HF magnets for holding files and other tools. They aren’t as strong as the tool trucks, but much less money.They should definitely be strong enough for kitchen knives, I have some good sized files hanging on them. With some imagination, they could be embedded into a wood strip, that would look nice. Leave the magnets exposed.

-- stay thirsty my friends...

View wunderaa's profile

wunderaa

243 posts in 1662 days


#7 posted 09-12-2014 12:37 AM

Just a thought to get you through this one….don’t rely on your block to hold the knives with the handle downward. Reverse them with handle upward and call it a day. Just let the knife shoulders help you out. Next time use 3/4×1/8” rare earth magnets. You can space them out to every inch and a half and be good to go. I much prefer your veneer technique…easier and cleaner in the end.

View Manitario's profile

Manitario

2397 posts in 2342 days


#8 posted 09-12-2014 01:47 AM

The magnets you used are too small; I used 1” magnets from Lee Valley and have no problems holding up my large knives. As well, you can set the magnets in metal cups which further increase their strength. See this article from Lee Valley:
http://www.leevalley.com/en/wood/page.aspx?p=40077&cat=1,42363

-- Sometimes the creative process requires foul language. -- Charles Neil

View runswithscissors's profile

runswithscissors

2172 posts in 1484 days


#9 posted 09-12-2014 03:27 AM

Could your knives be stainless? Though some stainless alloys do respond to a magnet, many do so weakly, or not at all.

-- I admit to being an adrenaline junky; fortunately, I'm very easily frightened

Have your say...

You must be signed in to reply.

DISCLAIMER: Any posts on LJ are posted by individuals acting in their own right and do not necessarily reflect the views of LJ. LJ will not be held liable for the actions of any user.

Latest Projects | Latest Blog Entries | Latest Forum Topics

HomeRefurbers.com