Tricky Repair - with pictures

[erictrumpet]

Hi all,

I am converting a gutted NBA Jam Extreme cab into a MAME cabinet and it is in beautiful shape except for one area of damage that was a bit tricky to repair, so I thought you might find it interesting to see what I did. The tricky part is that the area needing to be patched is visible from both sides, so I could not attach a patch piece using any other wood pieces or braces from the inside, as you might with a more typical repair.

Here are some pics of what I did:

The original damage. This is the right side just above the control panel. A very visible area!





So I cut out the damaged area and cleaned it up. Since it's a small area, power tools were pretty much useless here. I did this with hand saws, files, and sandpaper, checking it with a T square until it was a perfect corner.



Then I cut a patch piece to fit the cutout, and shaped it to match the other side. The other side has the little curve there so this also required a lot of hand-work to get the piece to fit just right.



Then I put the piece into an improvised vise for cutting the T-molding slot and countersinking the screw holes. The deep countersinks allow for the T-molding to pass over the screw heads. Under the screw holes, I drilled larger-than-normal pilot holes to prevent splitting of this relatively tiny piece of MDF. Basically, the screws do not "bite" this piece but merely pass through it and bite the cabinet wood only.







The next pics show installation on the cab. This was the only way I could think of to attach this piece invisibly, other than perhaps using biscuits and glue, but I've never done that before. Notice I used tiny washers on the drywall screws to further assist in preventing splitting damage to the new patch piece.





And here it is all done, with the T-molding reinstalled. It is a perfect fit, and once puttied and painted (I will be redoing the artwork on this machine), it should be strong and invisible.





Here is a picture showing the approximate location of the screws inside and how deep they hold into the cabinet sides.



Two questions for you all:
1. Do you think I should add wood glue to the joint? Presently it is held in place with screws only.
2. Any specific product recommendations for puttying the seam? Just plain ol' wood putty or something else?

Thanks for reading!

Eric.

[ChadTower]

Yes, I'd glue it, all along the seam.  Screws in MDF will eventually become loose if any sideways force is put on them.  And next time you don't have to be quite so exact on the fit of the new piece.  Bondo fills small gaps very nicely.  Nice job on what you did, though.

[Jdurg]

Incredibly good job there!  And yes, I would second the glue part.  Glue is typically stronger bonding than the screws are.  The screws just keep the pieces tight while the glue dries. 

[erictrumpet]

Thanks for the replies guys. I guess I should start a project thread about this cab... it's turning out pretty cool

Eric.

[facesmiths]

if you are still reading this thread I would like to
A. thrid the use of glue (probond wood glue is my personal choice. There is a bottle of it sitting next to me right now LOL)
B. I work with MDF and HDF (HDF is a hardness some where between medium density fiber board and hard board with only comes in very thin varieties and the surface is like glass while the back is textured much like canvas so the HDF is a great choice to get the best of both worlds) and I have found that it is no where near as prone to splitting as everyone thinks so drilling untill the wood screws dont bite at all is extreme and weakens your joint a tiny bit instead just over drill so ONLY the threads bite or even only the edge of the threads bite and you should be better than fine. in a pinch HDF is better than aluminum in most cases and nearly as good as using mild steel as it flexes less and all the only real draw back is it does absorb moister so it has to be sealed. that spot you have though should outlast and out perform the original materials that were used if you seal it properly to prevent moister from getting in (you might seal it with a wood hardener which will sink in and seal moister out but not stop the wood from being bonded with the glue) if you have trouble finding it just ask for something that is used on pine and such to make it harder to resist denting like in furniture(

[erictrumpet]

Hmmmmmm. HDF sounds like it might work for CPs. Is it stiff enough? Maybe it could be used for a CP if reinforcing ribs were glued underneath. This would eliminate the problem with using longer joystick shafts in thick wood panels which IMO destroys the feel of most joysticks by increasing the throw.
Regarding my joint, glue has been applied per everyone's suggestion.
And the pilot holes are probably allowing some of the threads to bite. But bear in mind that I was drilling right down the center of a piece of MDF so we are talking about just a tiny amount of material on each side of the hole just BEGGING to split wide open. (I actually made one piece, shaped it to fit, and split it when installing -- the final piece was version 2, with bigger pilot holes!)
Thanks for the input. I will check out HDF -- sounds useful for a number of projects. I made a desktop controller once with a 1/4" hardboard CP top, and I enjoyed working with that thickness but the controller was small so the lack of stiffness was not an issue (would not work for a full sized cab CP)

Eric.

[Hoopz]

Ironically, you have one more picture in your posting then Shawn Kemp has children with different mothers.   

Go count em!

Yep, I have nothing more to add here.   

[erictrumpet]

Ironically, you have one more picture in your posting then Shawn Kemp has children with different mothers.

Haha, this is funny as heck. Is that Sonics player Shawn Kemp? I am not a b-ball fan so I have no idea who these guys are. There are three different players on each side of the cab. I plan to change the artwork on this cab, so they'll all be gone soon.

Eric.

[Hoopz]

Yep, Shawn Kemp on your side art.  Originally committed to Kentucky then the infamous Emery package opened with roughly $10,000 in cash spilling out that was being sent to their recruits from an assistant coach.  He went right to the NBA and Chris Mills went to Arizona.  He was dumber than a box of rocks in high school.  Kinda sad actually.

One of my roommates in college played ball against him in high school.

[erictrumpet]

I wonder if Kemp or any of the other six guys on this cab actually own one of these machines. If I were on the side of an arcade machine, you'd bet I'd own one. I wonder this about Harrison Ford (and other actors) too. Does he own all the Han Solo action figures? Does he own a C-10 mint on card 1977 Kenner Original Han 12-back? I wonder what these b-ball players would think about me converting this cabinet. haha

Eric.