Vinyl over gatorfoam letters

[blackhawk]

I have a lead on some work, cutting out gatorfoam letters about 5" high. They described the letters as being covered with vinyl. I have only talked to the customer over the phone so far. I will be going to look at a sample next week. In the meantime, I wanted to educate myself a little bit. They said that the vinyl was applied to the gatorfoam first and then cut into letters. Is this something that anyone has experience with?

What type of vinyl might they be using and method of application?

Any suggestions on cutters, speeds, and feeds for this combination?
Thanks.

[signtist]

Brad, The vinyl should not effect the cutting at all. Just cut as normal using a down cut bit.

[blackhawk]

Thanks John. I forgot to also mention that the gatorfoam will be 1/2" thick. Is all the sign vinyl self adhesive?

[hol]

Yes, the vinyl is self adhesive.

We've cut a lot of gatorfoam with vinyl shapes applied to the face in the past - it cuts very easily. For .5" stuff we used a 1/8" single flute upcut spiral with a 5/8" cutting edge length, I think 2 ips or so with good results.

Larry Holbrook
www.blueridgefabrication.com (http://www.blueridgefabrication.com)

[jhicks]

Onsrud makes specific bits for gator foam type material. Check them out. They have a different cutter angle and cut pretty clean. Others may have good experience with conventional bits but geting a clean edge is the key.
Sample bits speed, feed and cut direction before running the real deal. I assume you have a vac hold down? That seems to work well BUT
Make sure you do NOT cut material directly over MDF spoil board!!!.
The dust will contaminate the edges of the foam and its impossible to get that dusty brown off the white foam edges.
We use a thin plastic sheet like sintra with holes cut behind the letters/ Inside the proile as large as possible so the vac holds down the foam inside the letters profile but the bit cuts into the sintra a shallow .01 or so and not the MDF.
have fun

[blackhawk]

Thanks everyone.

Jerry - I found the O flutes on the Onsrud website. I found a 62-7XX spiral O flute series and a 64-0XX "super" O flute series. Is one of these what you have used? Downcut or Upcut? Should I use the largest diameter cutter possible for my application?

https://www.onsrud.com/oc/pdf/O_Flute_Plastics_Brochure.pdf
https://www.onsrud.com/xdoc/SuperO

Thanks

[jhicks]

Brad, I use an UP cut but that is because we rely on our vac hold down so it really depends on how you are setting up. I suspect that a down cut would work fine since the material is so light and may not pack the cut with debris but dont know for sure.
I do prefer the Super O series though.
We use the smallest diameter possible so the inside corners are tight and the torque on the material is low. I have a 1/8" , 3/16" and a 1/4" plus a long one for 2" foam. I have even used the long (2" I think) 1/8" ball nose SB sells for 3D and it has a nice result plus a slightly tapered edge so it's all about how you want to experiment and the results you like with your set up and design goals.
Just dont forget to run a sample in climb and conventional to see which delivers the best edge quality. I think conventional may be the right way but its been a while and I test every time regardless just to be sure.

[blackhawk]

Thanks Jerry. Do you order directly from Onsrud or are there distributors out there with better pricing?

[jhicks]

Onsrud will not sell direct as far as I know so I buy from a local distributor or another shopbotter, Gary Beckwith who is an authorized distributor so you might want to contact him for prices as well. He knows the SB community and equipment quite well and may be able to help with other suggestions or recommendation as he has developed several custom bits with Onsrud.
check the forum search for his posts, web site link, and e-mail address.

[hol]

Another good source for Onsrud bits is http://www.hartlauer-bits.com/

They are quick to ship and always glad to answer any questions.

[blackhawk]

I just got my Gatorfoam today. I am trying my existing 1/4" spiral upcut from Centurion Tools before I try the O-flute. I am getting a great edge finish on both faces. The sandwich foam is pretty good also, but not 100% perfect.

My real problem is that the Avery vinyl will not stay in place at all during cutting. It is Avery A1840-S vinyl that my potential customer gave me to try. I applied it with a plastic smoothing tool made for applying wood veneer. I am cutting at 2.5ips and 16K rpm. I first thought that my dust boot was catching the edges of the vinyl, so I tried a letter without the boot, but no luck. I noticed that the Avery spec sheet listed the adhesion values based on a 24 hour setup. Does this adhesive have to setup that long?

The adhesive does not feel really sticky on the finger test. I wonder if the material has been setting around for a long time. The shelf life was listed as 1 year.

[blackhawk]

I let the vinyl set for 2 hours before cutting and it did do better. But it still peeled up on about 20% of the letter. The cut edge of the vinyl that did stick was awful. I am going to try a 1/4" downcut spiral tomorrow, maybe the upcut is pulling the vinyl off.

Good news is that I increased the RPMs to 19K and the sandwich foam looked great except for one small spot.

[dakers]

Brad, i noticed you are cuttin the brushed chrome vinyl which is probably polyester.
We have cut alot of brushed chrome but we use
this product which comes to us with the brushed chrome on it.
you can try cutting what you have mirror image with the brushed chrome face down. Never tried the product you have put together
take a look at this product.
http://www.ultraboard.com/ultraaluminum.html

A BRILLIANT ALTERNATIVE TO METALS
Elegant metal signs and letters can cost you and your client a bundle. Now there is a lightweight, less expensive, easily crafted alternative. ULTRA ALUMINUM delivers the same impact and appeal as metal, but in a durable, versatile foam-centered product.
Ultra Aluminum is the ideal material for decorative letters and logos often seen in hotels, banks and office buildings. It can be sawed or routed, and is easier to craft than solid metal. It even maintains its appearance better — the surface is anodized aluminum, which will not rust, fade or tarnish. The back side is high-impact polystyrene.
For metal lettering and logos, Ultra Aluminum gold and chrome are the obvious choice and can be used in place of other sign materials.
Ultra Aluminum comes in four finishes — polished gold, brushed gold, polished chrome, and brushed chrome. Choose from white or black core, thicknesses from 3/16" to 3," and 48" x 96" sheets or custom-cut sizes. Two-sided aluminum panels are also available.
BRUSHED GOLD BRUSHED CHROME POLISHED GOLD POLISHED CHROME

[jhicks]

Good suggestion on the ultra board.
as usual need a bit for this to cut a clean edge but they do make them in a nice 1/8" diameter so cuts and corners are quite nice.
I generally cut aluminum skin 1st at a shallow depth, then 2nd pass all the way through to keep aluminum chips from getting into the foam layer and sides of the pieces but may be able to run in a single pass.
That material or its competitive brands is definately the way to go.
Simple cut and ship.

[blackhawk]

Thanks for the Ultraboard info. I requested one of their sample packs. The cost over Gatorfoam looks to be a little more than double. Maybe the savings on vinyl and labor will still make me competitive

In the meantime, any ideas on cutting the vinyl with a clean edge? They are already buying these letters made in this way, so there must be a way to do it.

[dakers]

Brad, i am not sure if the problem is adhesion, router bit, the avery brand of brushed chrome or something else. I would probably start by talking to Avery about it. I know there are alot of manufacturers of brushed chrome in cast and calendared, 2mil and 4mil with different properties. if adhesion is issue you can prime, enamel the gatorboard with gloss enamel which will give you better adhesion or use the 3m adhesion promoter liquid.
do not use latex primers as they may warp board.
or you have old material which may come back to life if you run a hot iron over the vinyl using a towel between iron and vinyl or use heat gun, hair dryer. Heating the adhesive will definitely let it bite better. You have probably already done all this as but that is where i would start if i was not crazy yet. if it is a router bit issue i am not sure what to use. did you try a straight bit with one flute? If not try that. I really do not know for sure what you can do but i have been in your shoes so many times that the shoes are worn out.

[blackhawk]

Well, the downcut spiral cutter did the trick. The vinyl cut looks perfect now and the downcut did just as good on the gatorfoam as the upcut! The bottom 20% of the sandwich foam next to the spoilboard is a little rough. I am going to try Jerry's method of using something like Sintra to cut into besides the MDF. I am using carpet tape since I don't have vacuum. When you hit the carpet tape it makes somewhat of a gooey mess near the bottom. I will have to plan out my tape placement for the real deal.

I think the ultra aluminum would really be the way to go. I will cut a couple of letters out of my sample pieces and see if the customer goes for it. I think the extra cost will be worth it for the quality of a real aluminum skin.

I appreciate the help a lot.

[mklafehn]

I have cut alot of small gatorfoam letters, however most have been without vinyl applied because I paint them afterwards.
I have tried many a bit and the only one I found that cuts gator well and the edges look like they were laser cut was the .0625, 3 flute bit from Precise Bits.

Here is a direct link to the order page:
http://www.precisebits.com/products/carbidebits/ultrabit-soft.asp

Order #MM3I8-0625-031F

The only downside is you have to order $50 worth of bits (about 5).

The nice thing about this bit is you don't need vacuum holddown because the shavings stay in the kerf. Once the letter is cut, you can remove it from the board and brush away the shavings.

Settings: 18k @ 3ips

Again, I haven't tried it with vinyl, but for clean cutting small letters this is my bit of choice.