Jump to content
Note to New Members ×

How to repair Core shots on Metal boards.


Fleaman

Recommended Posts

So I put a core shot on my new Coiler AMT 177 and was wondering how to fix it. I Emailed Bruce and he said he does'nt repair boards, he just builds another one when he breaks it. Haha, but seriously, he recommended taking the base down 2/3 the thickness and epoxying a patch in the area. This is required because if the anodized titanal under the base is scuffed, it will be hard for p-tex to stick.

So I was a bit leary taking a Dremel router to my board but I did and the repair turned out satisfactory. It isnt perfect but very useable.

If anyone has ideas or other techniques, please post your ideas.

Here is a picture of the core shot.

DSCN7672.jpg

Another angle

DSCN7673.jpg

What I did is cut out a patch first then laid it on the base and traced it out to remove the material with the dremel router.

DSCN7674.jpg

I then sampled some of the cookies my wife made earlier. Yum Yum

DSCN7675.jpg

All I had at the time was a round burr bit. I think a cylinder one with a flat bottom would be preferable but this is all I had.

DSCN7681.jpg

Starting to rout out the base 2/3 the thickness of the p-tex

DSCN7682.jpg

The hardest part is to get the area cut out the same shape as the patch. The epoxy will fill in any gaps but they are unsightly but I dont care that much. I did the best I could without a template. You can get some at tognar.com

DSCN7684.jpg

The patch fits fairly well.

DSCN7685.jpg

Then you have to sand the areas to be glued, keep it away from the metal to keep the anodization . then flame treat the p-tex patch and the base and clean with some acetone. You might want to let the acetone evaporate off the peices for a while before you flame the areas. :angryfire

DSCN7687.jpgDSCN7686.jpg

Then use some High quality epoxy, I used Hysol from Tognar.com

DSCN7688.jpg

Prepare your clamping pad and clamps. I have found that wood with base protection tape does not stick to epoxy.

DSCN7689.jpg

I then protected the area around the repair from accidental epoxy drippage.

DSCN7690.jpg

By this next step you should have drunk at least this many beers, if not, chug a few and be happy.

DSCN7691.jpg

the area all clamped up,

DSCN7692.jpg

Everything peeled off a few days later.

DSCN7693.jpg

side shot of the repair

DSCN7694.jpg

top shot

DSCN7695.jpg

some tools I used to take down the patch level with the base. I used the draw plane the most, it is sharp and will damage your surrounding base ifyou are not carefull. I found pulling it on an angle like a file worked the best. As you can see in the next few shots I did drag it on the surrounding area and made a few light gouges.

DSCN7696.jpg

The completed repair, sanded a bit and then rubbed with a scotch brite pad.

DSCN7697.jpg

It isnt perfect but it is an effective repair. A template would make the patch fit nicer. Notice the tool gouges from leveling the patch.

DSCN7698.jpg

Thats all, Now a wax and then go riding.

Link to comment
Share on other sites

I uploaded the pictures to Photobucket and linked to them in my post with img tags.

like this

but without the * in IMG [iM*G]http://i19.photobucket.com/albums/b171/fleagalbaum/board%20repair/DSCN7698.jpg[/img]

there is a link on the photo page you can click and paste in your posts. The captions are written before or after the link

Link to comment
Share on other sites

Nice work Fleaman! :biggthump

Can you or Bruce tell us more about the "flame treat" part of the process? Do you just slightly melt the Ptex before bringing the parts together?

All you need to do is pass a flame quickly over the parts a few times so it opens up the pores of the p-tex. If you hold it too long, it will melt it a bit and it wont stick.

Try it with an old board or patch of p-tex first to get the idea.

Link to comment
Share on other sites

Looks like you had the tools, talent, and cajones. I wouldn't trust myself with that job! Thanks for the interesting pics.

Before I took the dremel to the board, I measured 3 or 4 times then took a deep breath and chugged the rest of my beer.

You now officially are more qualified than me at doing that type of repair:biggthump

Nice work! I have yet to see anyone do that yet and as long as you did the flame treat effectively( which is pretty easy), it should work out nicely.

Stay off the rails next time:freak3:

BV

Thanks for the idea. It was pretty easy to do it, just time waiting for the glue to dry.

Link to comment
Share on other sites

I rarely do repairs like this, but have done some. You've done what I do for the most part. I would have set up a router with a template (cut on the cnc) and cut all the way through the p-tex. This involves some tricky adjustments, but with a dial indicator you can usually make incremental depth adjustments of about .005in until you are through the base. I then use our cnc to cut multiple patches each .005in bigger than the next. When I find the one that fits the best, I use it. The patches I've done have been much bigger. As long as 40in. I put the board back in a press rather than clamp. It then gets a base grind.

If the metal is directly under the base, it does present a problem. If you lightly sand the aluminum minutes before applying your e-poxy, you should get a good bond. aluminum will oxidize. This is what prevents adhesion to it. By sanding immediately before applying your epoxy, you should get an extremely good bond.

Link to comment
Share on other sites

I wish I had a way to be more precise, but I am a backyard tuner.

Maybe with a large peice of metal for a template you make the cutout really large so the dremel fits inside to remove material. Then the problem lies in cutting the patch out the right size.

I would have used my CNC machine but I sold it for some beer and cookies last week :D

Link to comment
Share on other sites

Actually I heard a couple years ago that Sears had plans to produce a bench top cnc router. I don't know what happened to it. If you look online, there are multiple plans for bench top units that carry a small router or dremel. There are even plans for converting mini mills for cnc control. Most of them are adapted from discarded printer and floppy drive stepper motors.

The only metal I cut with my cnc is the titanal laminates that go in our metal boards. Everything else is wood or plastic.

You could cut a template large enough to fit the base of a dremel and your shape. It is actually possible to do the entire job this way, including cutting your patch. You would simply cut your template to run your dremel inside of (this could be done with a jig saw). Cut your base material by running the dremel around the outside of the template. To cut the base material off the board, you would need an offset shim inside the template equivalent to the radius of your dremel bit. If your template is square, just place strips of wood along the inside edges of the template that are the thickness of the cutters radius and begin cutting.

Link to comment
Share on other sites

Actually I heard a couple years ago that Sears had plans to produce a bench top cnc router. I don't know what happened to it. If you look online, there are multiple plans for bench top units that carry a small router or dremel. There are even plans for converting mini mills for cnc control. Most of them are adapted from discarded printer and floppy drive stepper motors.

The only metal I cut with my cnc is the titanal laminates that go in our metal boards. Everything else is wood or plastic.

You could cut a template large enough to fit the base of a dremel and your shape. It is actually possible to do the entire job this way, including cutting your patch. You would simply cut your template to run your dremel inside of (this could be done with a jig saw). Cut your base material by running the dremel around the outside of the template. To cut the base material off the board, you would need an offset shim inside the template equivalent to the radius of your dremel bit. If your template is square, just place strips of wood along the inside edges of the template that are the thickness of the cutters radius and begin cutting.

HUH?

Hey man you're talking to Canadians eh, if theres any more than beer and a chainsaw involved , we're not interested:lol:

Link to comment
Share on other sites

HUH?

Hey man you're talking to Canadians eh, if theres any more than beer and a chainsaw involved , we're not interested:lol:

I'm assuming the use of the dremel base pictured in Fleamans original post. If you want a square patch 2in X 2in and the base of that dremel tool is 2in in diameter, you make a square hole in a piece of plywood that is 4in X 4in. When you run the 2in diameter demel base around the perimeter of that square hole, the bit will cut a square that is 2in X 2in. The only thing that remains is to adjust for the thickness of the cut when going from the patch to the hole in the base. Above I stated the shims should be the thickness of the bits radius. That was wrong, it should the thickness of the bits diameter. Your patch will have square corners, where your cutout will have rounded ones. It will be necessary to square the corners on your cutout or round those on the patch. If done correctly, you should get a very good fitting patch and cutout.

Link to comment
Share on other sites

A small tip:

Using small sandblaster that some dentists use, such as MicroEtcher (below), helps adhesion when used with 90- or 100-micron aluminium oxide powder. Can improve bonding between metal and resin immensely (twice or more), and takes only a few seconds. Also removes any loose debris and is not aggressive like typical industrial sandblaster so it won't pucture thin metal layer or topsheet. Ideal for small applications such as the case above or fixing small delam...

d_22005-01.jpg

Problem? You need to buy an air-compressor, not to mention acquiring microetcher handpiece which can cost more than $1000. Therefore, you will need a dentist who has it, is either a skier or a carver and is a good friend of yours... I was lucky! ;)

Link to comment
Share on other sites

I'm assuming the use of the dremel base pictured in Fleamans original post. If you want a square patch 2in X 2in and the base of that dremel tool is 2in in diameter, you make a square hole in a piece of plywood that is 4in X 4in. When you run the 2in diameter demel base around the perimeter of that square hole, the bit will cut a square that is 2in X 2in. The only thing that remains is to adjust for the thickness of the cut when going from the patch to the hole in the base. Above I stated the shims should be the thickness of the bits radius. That was wrong, it should the thickness of the bits diameter. Your patch will have square corners, where your cutout will have rounded ones. It will be necessary to square the corners on your cutout or round those on the patch. If done correctly, you should get a very good fitting patch and cutout.

I wish I got enough riding in to damage a board.

Link to comment
Share on other sites

HUH?

Hey man you're talking to Canadians eh, if theres any more than beer and a chainsaw involved , we're not interested:lol:

Oh, I had a flashback to when I was a kid growin' up in Wisconsin...neighbor wanted a picture window in his house, fired up the chainsaw, cut studs, nails, siding, whatever was in the way. Fairly certain there was beer involved...

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.



  • Recently Browsing

    • No registered users viewing this page.
×
×
  • Create New...