Spoilboard - Double Stick Tape?

[ryan_slaback]

I notice a lot of posting regarding methods of holding down the spoilboard. I work in a school and there is a very real possibility that a student will plunge too far or in some other way cause the router to hit a fastener. I know that there are plastic screws available but I was curious if I could just use a few strips of carpet tape. I know that can be used for part hold down. Is there any reason I can't use it to hold down my spoilboard too?

[mikejohn]

I have a 3/4" table, bolted dpwn with inset coach bolts, with a MDF spoil board glued on top.
When the spoil board is new, you can plunge an inch without the fear of touching anything.
Having said all that, I guess sufficient double sided tape would work.

................Mike

[Brady Watson]

Ryan,
Glue the spoilboard to the base board. After you surface it to the point that it is getting thin, just glue down another sheet (MDF, Medex, whatever) and you don't need mechanical fasteners. Plus, the spoilbard will stay flatter than if you had used screws alone. A 1/2 gal of wood glue will do the trick.

-Brady

[paul_z]

Ryan,

I made a stupid mistake when I glued the latest piece of spoilboard onto my table. I didn't make sure the glue was all the way to the edge and there was a small void at the edge going in about 1". This wouldn't have been a problem except that's precisely were I use a lot of clamps and the clamping force would deform the edge and tip or deform the part to be cut. I had to drill a bunch of holes and force glue in where it should have been. Take Brady's advice; use lots of glue and get it all of the way to the edges.

Paul Z

PS MDF really sucks up the glue. If it looks like you have barely enough, then you've got about half of what you'll need.

[pete]

Ryan
I have used nylon or plastic toilet seat bolts to hold the spoilboard to the base board before. You drill through the spoilboard and baseboard, of course. Recess the bolts into the spoilboard a bit to allow for surfacing the spoilboard. I put one at each corner and midway between corners on all sides (48x48 machine - larger machines could use more bolts). So even if you run a bit into the nylon or plastic bolts while routing or surfacing the spoilboard there is no damage to the bit. Don't overtighten the bolts as you install them. Just another idea. Pete

[trakwebster]

MSC Industrial (http://www.mscdirect.com) carries a number of bolts, spacers, and nuts made of nylon. Don't know if they have great big ones or not.

[chiere]

Hello, I have lots of question about spoilboards and glue as well, mind if I butt in? =-) (Rails, too,...)

I work in a foam shop, making archetectural foam elements, momument signs, and bas relief & 3/D sculptures, so I know my jobs are pretty 'fluffy' compared to the rest of y'all's, =-)

Our (MY!! =-) SB is going together slowly, and it is now time to put the boards on. We are going to use MDF, and my first question is, I am in Florida, near the East coast, and this stuff has been laying around the shop for two years. Might I assume it has sucked up as much moisture and warped as much as it's going to by now w/o throwing a bucket of water on it? (Which is what it feels like on some days,...) So, after all the fiddling and leveling and plaining the first time, will I still have to worry about further warping?

When bolting down the support board, what is the best pattern recommended? We have the 5'x10' SB w/the big blue table. Every cross piece has 10 bolt holes. Do we use them all? Some are only 8" apart. That seems a bit redundant,...

I really like the suggestion of glueing down the spoiler board, then just tossing another on top when the first gets leveled down enough. We use a pretty strong expanding foam to assemble our products, and we sell it to the plasterers as an insatllation glue. It's called Enerfoam, here's a link, http://www.dow.com/buildingproducts/enerfoam/

Even tho it's made to expand, we mush the parts together, breaking down the foam, let it get tacky, then stick it. All our foam survived 3 hurricanes two years ago. Can I use it to attach the spoiler board? Once on, it ain't commin' off. Would this cause a problem later on?

I plan to hold the foam to be routed down w/ double stick tape. Are there problems with lifting that I need to be aware of as foam is so light? It does cut like butter with a sharp bit,...

Rails,... I wasn't here for the assembly, and there was much cussing and sweating involved with the assembly. In other posts I noticed folks were using micrometers to judge gaps, spaces and for leveling,... Do I need to be worried that my shop goons didn't do a thorough enough job? What do I look for? What should I worry about? Can I just fire her up and see what she does before I worry?

Who else uses their SB in the foam industry? Are there threads for that? (I have done lots of looking, but haven't come across one yet, but I haven't seen every thread yet, LOL!)

And, how many women do we have using the SB? (not tecnichal, true, but I don't want to feel alone, LOL! There has to be a Sisterhood of the ShopBot,...)

Please forgive my lengthy post, I have apparently been saving up!

Later,
Cheri'

[dhunt]

You're one of the v.few ladies in here, Ma'am.

And I believe I'm right in saying that MDF (in your, and my, kinda climate)
will expand and absorb ad infinitum.
If your sheets are already 2 yrs. old,
unless they're badly warped, sure you can use them,
but you'll need to resurface/flatten it/them, using a large dia. flat bit,
(these days made for the purpose).

You should consider a brand new 3/4 inch plywood base-board
(quickly sealed/varnished,if only along its vulnerable edges, as soon as you get it home from the hardware - for sheer longevity)...

...and a brand new MDF sheet(also 3/4inch) for that first spoilboard to be glued to the baseboard.

Unless your budget demands it, you shouldn't scrimp on these 2 'first-of-all-boards' to go on your new machine.

[beacon14]

Use every hole. The less chance for vibration and warping the better.

As for the rails, disengage the motors and slowly roll the gantry along the rails, while carefully watching each wheel (do this repeatedly for each wheel) If there are any spots where any of the wheels lift off the rail, or ride badly up to one side or the other, you may want to consider re-setting your rails. If all four wheels stay in good contact with both sides of the rail along the entire length of the rail you are probably good to go cut foam all day long.

[mikejohn]

Cheri
Is this (http://www.talkshopbot.com/forum/show.cgi?tpc=2&post=31692#POST31692) the sort of work you are doing?

..........Mike

[gerald_d]

http://www.artisticfoamdesigns.com/ - from Cheri's profile

My impression is that the foam work is fairly low tolerance stuff (gets thick coatings afterwards) and that the SB shouldn't need any further checking and tweaking before going to production. I would run it as is to shake it down and fiddle with it later.

[sallye_c]

Hey Cheri. Bill Young alerted me to the question of whether there are other female ShopBotters out there. Off the top of my head, I can give you the names of a couple of women. BJ Wilkerson in the northeast makes children's furniture...leadmare at metrocast.net (mailto:furniture...leadmare@metrocast.net). There is an industrial chemist turned signmaker in NC. Jillian Northrup www.becausewecan.org (http://www.becausewecan.org) is part of a team that does very creative work with a benchtop.

I teach a women's class at the ShopBot Jamboree every year, and there are usually 20 women who participate. Some are wives who are trying to understand what their husbands are doing, and some are important parts of their business. We usually have a lot of fun. I've worked in foam (see the ShopBot spotlight about the elephant), wood and signmaking.

Here's a somewhat practical answer to whether you need to tweak your machine more. Take a V-bit (any angle, but the wider the better) and a scrap piece of foam...the bigger the better. Then, cut a shallow rectangle ( .05 - .1" deep)(the bigger the better) in the foam, and a line or S curve across the diagonal. Look at the cut and see if the width of the line changes as the tool moves across the material. If the width of the cut doesn't vary, or not enough for you to worry about, cut in peace. If it varies, then either the table is not flat, the foam is not held down evenly, or the rails are not set up correctly. While you are there, measure across the diagonals of the rectangle...if they measure the same, your set up is square. If not, you have some tweaking to do.
Good luck, and welcome. Sallye

Sallye at GoodHarborBay.com (mailto:Sallye@GoodHarborBay.com) or Sallye at shopbottools.com (mailto:Sallye@shopbottools.com)

[chiere]

Thanks for the input everyone!!!

Yes to both Mike John and Gerald D, that is what I have done, and plan to do again, =-) The company I work for now has been doing the column capital crown moulding thing since they set up shop 6 years ago, and I joined them 5 years ago. Before that I worked for a company called Cinnabar in Orlando who did the big 3-D billboards, themed entertainment construction, and movie and commercial sets. Talk about getting paid to play!!! I also got to work with the team that sculpted the Daytona USA Ghost Cars (produced using the same method as the stallions Mike John provided a link to. I call it the sliced bread method, LOL!)

Thank you Sallye for your response as well, =-) It's nice to know there are a few women out there who love large noisy bits of machinery as well! I also am fascinated by cranes, LOL! My husband keeps trying to talk me into buying an economy car. I am insisting on the biggest truck I can afford,.... Gotta pull a horsetrailer w/ draft horses!

I liked the elephant! I had already pointed it out to my boss, as we are bidding a job that will probably use the same techniques.

Now I head to work tomorrow with a shopping list (new boards, thanks David,) a bag full of carriage bolts, and several tests to perform!

After that, I am sure there will be more questions, LOL!

Later, Cheri'

[joe]

Cheri,

One way to avoid all the fancy hold down issues, such as double stick tape, is to route down to a couple of thousandth of the bottom of the material. By doing this, you can clamp the sides of your material to the router bed. Your foam will be held very secure. When finished you can push the letters right through.

Some of my friends apply premask to the back of th e board and route down to that. Then you remove the premask, letters and all.

verks for me.

joe
www.normansignco.com (http://www.normansignco.com)