Help repairing MFT/3 tabletop

[wolfie]

Hi Guys,

I've read lots of great stuff on this forum and have just become a member hoping to get some advice.  Sadly (and embarrassingly) I've accidentally cut a very deep kerf into my MFT/3 tabletop.  It's 5/8" deep and is the work area where I make my crosscuts.  1 more 1/8 inch and I'd be through the top.  The top still seems solid, but I'm thinking I should probably be proactive and try to repair this before it becomes worse.  I've read various repair discussions on this forum, but I don't think I've come across any discussions that discuss repairing a kerf as deep as mine.

My idea right now is to fill the kerf with (Minwax High Performance Wood Filler and sand flush.  Then I would clamp a wood support across this weakened area (using the dog holes) to support it as I removed the top, rotated it, and flipped it over.  This would put the "bad" spot on the other side of the table, where I don't make cuts.

Does this sound like a good solution to anyone that's done anything similar?  I've never removed or replaced the top, so I'm coming at this from ground zero.

I've attached some photos... and yes - I nicked the aluminum, too!

Thanks in advance,
Rob

 

[Slartibartfass]

I used some wood filler in the past and have used shellac to cover the surface. So far none of the fixed areas have crumbled.....

 

[Grev]

The minwax may work fine .. never used it, but I have used bondo in the past to fill rotted wood areas and it works great.  Just make sure the kerf cut is cleaned out good. .. you can get it at HD or Lowes.https://www.lowes.com/pd/Bondo-28-oz-Gray-Patching-Compound/3044443.  Another option would be an epoxy resin . . I believe it would soak into the wood fibers.  Do an search online .. plenty of them out there.  Good luck.

 

[DIY WoodWerx]

Maybe route a groove for removable insert. When the kerf gets worn then it’s replaceable.

I found this idea reading different posts.  Did it to my DIY MFT top

 

[Klemm]

[member=67737]wolfie[/member]  - don't overlook the ease of making your own brand new - and really accurate - MFT  top using the Parf Guide System. It's so easy to get exactly what you want with a Parf Guide System in your shop. You can see it on our website www.tsoproducts.com.
Then you don't have to "be careful" of cutting into the top - it's just another replaceable/disposable worksurface.

For repairing, the BONDO approach will get  the job done as the other posts suggest.

Enjoy your woodworking!

Hans

 

[Dick Mahany]

I have used Durhams Rock Hard Water Putty in the past with success.  I have also used Bondo.  I think either would work well.  I'd take a q-tip and some acetone or IPA and clean out the kerf very well to get a good bond.  You could also roughen up the sides of the kerf lightly with sand paper to give it some tooth.

 

[nclemmons]

+1 on Bondo to repair.  It dries hard and stays in place.  The top can be easily reversed. Four bolts and you're back in business. 

 

[wolfie]

Thanks everyone!  Would you bondo and be done, or would you flip and rotate the top, too, to get this spot out of my work area?

(Hans - I'll check that product out for future use, thanks!)

 

[peter halle]

Just rotate the top if your OOPS is to the right.  Then you have a flip coming in the future with a clean surface.

Peter

 

[wolfie]

That sounds like good advice Peter - I'll do that!  Cheers guys!

 

[Administrator_JSVN]

Hey, Rob. We got your email earlier today, and someone from our customer service team will be reaching out to you shortly about the MFT too.

Once they do, let me know if you need anything else.

(Tyler)

 

[wolfie]

Hi Tyler,

I hate to say this on a public forum, but you brought it up, so here it goes.  Festool did respond to my inquiry, but I was extremely unimpressed with the response.  I had specifically asked Festool if they could suggest a repair option for me, and my question wasn't acknowledged at all.  I was simply told that I could buy a new tabletop.  I could understand if the emails was something along the lines of "gee Rob, that's a pretty bad kirf, and I'm not sure I'd trust a repair....yada yada", but there was nothing like that.  I was simply told I could buy a new one.  Here's a copy-and-paste from the email:

"Thank you for your inquiry concerning your MFT3 table.  The table top for the MFT3 is replaceable.  You can contact our Customer Service Department and they will be happy to assist you with pricing and shipping information.  The part number for the replacement top is 495543."

After receiving that non-answer, I came here.  I've never dealt with Festool support before this, maybe it's not always like this, but as I said, I wasn't impressed.

 

[Birdhunter]

I used two part epoxy wood filler to repair a goof. I think it is stronger than bondo.  I pounded it into the kerf and, once dry, sanded it flush. Several years later, it’s still solid.

 

[wolfie]

Hey Birdhunter, the wood filler I have is a two part solution as well, but the stuff I have is a paste so it sounds different than yours.  I'm thinking I'll try the Bondo since I have to go to Lowes this evening and TrackTubesGuy mentioned they sell it there, and it sounds like lots of folks have been satisfied with it.

Does anyone know about the hardness of Bondo and how it might affect a saw blade?  I'm planning to rotate the table, so it will be out of my main cutting area, but it's possible I could, at some point, want to cut lengthwise along the table, thus through the Bondo.  Is this a cause for concern?  I could always lay a sacrificial scrap on the tabletop to avoid cutting through it, if necessary.

 

[Peter_C]

As suggested by DIY Woodwerks, use a router to cut a grove and glue in an insert. Fresh start! The strength will be there too. Bondo, and other types of repairs will not be very strong, and if that is the option it is not worth trying to fix.

 

[wolfie]

Is routing a groove an option in my case?  My kerf is quite deep, having only 1/8” of table left below it.  Would I just route a 5/8” deep dovetail? (I found some discussion on routing a groove on this forum and at least one person routed a dovetail).  Thanks!

 

[Peter_C]

Screw it down to a piece of plywood first, then route the grove. That will keep it stable. You can use washers, or the like, and screw it threw the 20mm holes. Although putting a few small holes in the top won't make a bit of difference. Don't unscrew it until the glue has dried. If it is as thin as you say you may need to screw it before removing it from the MFT itself, so it doesn't break.

 

[sancho57]

Ive made the insert, mine was replaceable, I routed a 2" wide channel 3/8 deep. Planed down a piece of scrap hard wood, screwed the insert it down making sure the screws were in the cutting groove and sawed away, when the insert got to jacked up, just replaced it. I flipped the top bc well it got to beat up and Im still using the top been about 5 years or so.

Bondo'd it just kept on sawing

 

[wolfie]

So Bondo sounds super easy, and at first I though routing a groove for an inlay might be too time consuming / overkill / beyond my skill level, but the more I think about it, the more I’m interested in trying this.  I wouldn’t want to keep screws in my tabletop (for a removable insert) as I wouldn’t trust myself not to cut into those at some point.  So I would glue the insert in.

I have a router attachment for my guide rail.  I’ve not used it yet, and this could be the perfect opportunity to try it

I was thinking maybe a 3/4” wide, 1/2” deep groove.  I’m too nervous to make a groove as deep as the kerf, as that would only leave an 8th of original mdf intact.  This means there would be 1/8th kerf under my inlay (i.e. a hollow spot).  I think this would probably be okay, given my impression that 1/4” kerfs in the top don’t seem to weaken the table severely.  Also, my glue would fill this void, which might help mitigate any weakness it might cause in the table top. I thought about filling with Bondo or wood filler first, then routing, but wasn’t sure if this extra step would be warranted.

I’ve never made an insert. Should I make it slightly undersized on the sides to account for glue?  If yes, how much?  Maybe a 16th (32nd on each side)?

Does it matter which material I use for the insert?  I have lots of pine.  I might have some oak.  I don’t mind purchasing mdf if that makes sense. I would use my tablesaw to cut it down to size. I’d use tight bond 3 for the glue up.

One adavantage to routing 1/2” deep is that I would just clear the aluminum on the sides of the table, which means I could do this in place (without removing the table).

Thanks very much for the discussion so far, I really appreciate it.

 

[nclemmons]

No need for a really tight fit if you are gluing it in place.  Pine should work fine.  how about a 1/2 wide by 1/2 depth?  No real need to go the 3/4 width unless that is the space the current kerfs cover.  The bottom kerf that you said is a little deeper can be filled with glue and it will harden and be plenty strong.  A piece of painters tape on each end will keep the glue from escaping till it hardens.  Leave slightly proud (1/64) on the surface and sand flat when it is hardened.