Best scratchbuilding foam? - Page 2 - RC Groups
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Aug 11, 2017, 10:51 PM
Tinkerer extrordinaire
I think part of my reluctance of using DTF inner is that the HK foam is $15 for 20 sheets (20x30 approx). The DTF is $1 a sheet, which is more expensive. Combine that with being able to use it out of box, without bothering with getting the paper off; and it is more hassle for more money.

A few questions about DTF:
How would you peel the paper off? The stuff I had, the paper came off in little shreds.
How paintable is the DTF?
How flexible and crash resistant is it?
What thickness is it?
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Aug 13, 2017, 10:49 AM
Registered User
OK.. Usually there is No shipping charge when you buy at your local $ store.
Shipping on foam is more than the foam.. usually.
Paper on $ foam usually peels off in one piece, especially so after it's been wetted.
As for the rest: Splurge! the 1$..... and experiment.
Aug 13, 2017, 01:16 PM
12th Pursuit Squadron
TheAeronut's Avatar
The Dollar Tree foam may not be perfect, but it is pretty good for models. One of its better features is that it is not brittle, rather resilient. Peeling the paper off of the Adams board is not difficult, and in most cases is done in one piece. I like working with it.

Similarly, while it is not the cheapest alternative, MPF is not the most expensive option either. Best yet, its consistency is excellent. Almost as resilient as DTF while being a bit more rigid and still easily workable, including simple and compound curves. If a box of 16 sheets is too much for you, I am sure that you can find some friends to split an order with. One caveat though, once you start building with it, you might want the whole box for yourself.

J.P.
Aug 13, 2017, 03:12 PM
Retired CAD guy
birdofplay's Avatar
MFP is USA made not imported.
It uses the USA standard of 2' x 4'

It's more resilient than Depron "WAS" !

MPF is not "cheezy" like the last "so called" depron that I tried from HK .
Sanding the HK depron was also BAD as it seemed to just shred vs sand off.

I suppose that Peeled off papas Dollar Tree is good for substituting for 3mm projects.

I still have many sheets of 3mm Depron but
I use ONLY MPF for everything else.
I've updated ALL my CNC programs to use the new 2' x 4' format.

Well ok ...
if it's a giant I use 1/2 "construction foam Green or Pink - since blue is way to hard to find.

Bob @ Hoosier Cutout Service
Aug 13, 2017, 04:56 PM
Hot glue held together by foam
balsa or carbon's Avatar
Quote:
Originally Posted by birdofplay

MPF is not "cheezy" like the last "so called" depron that I tried from HK .
Sanding the HK depron was also BAD as it seemed to just shred vs sand off.
HK does not claim that their foam IS depron ( it's XPS ) , only that it's "very similar" to depron . ↓

I use it because I live in Portland and pick it up at the HK USA warehouse ( no shipping charges ) , so in my case it really is just 67 a sheet .

But when comparing costs for products , always compare TOTAL cost including shipping .
Aug 13, 2017, 08:02 PM
Retired CAD guy
birdofplay's Avatar
Shipping is killing the little Mail order places.

Even the The Amazon Air fleet is now as big as FEDEX !
Aug 13, 2017, 09:01 PM
Registered User
Quote:
Originally Posted by birdofplay
MFP is USA made not imported.
It uses the USA standard of 2' x 4'

It's more resilient than Depron "WAS" !

MPF is not "cheezy" like the last "so called" depron that I tried from HK .
Sanding the HK depron was also BAD as it seemed to just shred vs sand off.

I suppose that Peeled off papas Dollar Tree is good for substituting for 3mm projects.

I still have many sheets of 3mm Depron but
I use ONLY MPF for everything else.
I've updated ALL my CNC programs to use the new 2' x 4' format.

Well ok ...

if it's a giant I use 1/2 "construction foam Green or Pink - since blue is way to hard to find.

Bob @ Hoosier Cutout Service
That's primarily because You use it in your "basement" business cutting Flat foamy bits for resale .
Why? someone would even want precut depron (or facsimile) model parts simply boggles My imagination.
But Hey ! a buck is where you find it.
MPF is actually XPS sliced into Depron thicknesses.

IF one was Cheap and didn't want to pay shippings... a Hot wire, a couple of thickness jigs and some DOW foam (USA made :-) would make for a very good alternate. Add in a #11 exacto blade and instant Kit
Hey! whatever floats yer boat.
Aug 14, 2017, 09:08 AM
Retired CAD guy
birdofplay's Avatar
Trying to understand this veiled affront , so let me explain a few things.

My shop is not in the basement.
It's currently in my Shop and was started in a two stall garage.
It's been popular enough to keep me going since 2005.
Bob's New Shop in Indiana (4 min 4 sec)



Model Plane Foam is NOT sliced whatsoever.

It comes with a relatively shiny and smooth, but not skinned, surface.
It is Extruded to it's delivered thickness by Adams in Michigan.
MPF is XPS - eXtrudedPolyStyrene

It is NOT Bead foam AKA - EPS ExpandedPolyStyrene

Bead Foam or EPS is much less dense and is easily Hot Wire Slice-able
XPS on the other hand is NOT so as easily sliced.
The Two types of foam are NOT the same thing nor should they be used for similar purposes.

To paraphrase an very old TV show ...
" There are 8 million stories in the city"

Some guys don't have the time or patience for Printing, Pasting, cutting out, Taping
all those details.
Others just don't have the time or patience or in some cases skill to cut out the pieces.
I provide a Service , in my retirement, and charge a very small fee for doing it.

If SOMEONE does not actually make money ,
Then where will the government get their taxes for Roads, schools, and defense ?
Last edited by birdofplay; Aug 14, 2017 at 11:10 AM.
Aug 14, 2017, 10:42 AM
Tinkerer extrordinaire
Basically, once I did a complete cost breakdown, here are my results:

MPF: great foam, full box of grade A ends up about $70 including shipping, which makes it close to $9 a sheet. Ouch!

DTF: decent foam, half the thickness I need, so I would have to double it up, which makes it $2 per usable sheet.

DOW blue foam: slice 4x8x0.75 sheet ($15 at local lowes) into 12 2x4x0.25 sheets. Ends up $1.25 per sheet

HK xps, when you count in shipping, it costs the same as the DOW, for an inferior foam.

I'm thinking rigging a hot wire to cut DOW is my best option.
Aug 14, 2017, 11:04 AM
Retired CAD guy
birdofplay's Avatar
The boxes that I buy have 16 sheets per box.
$70 / 16 sheets = $4.375 per sheet.
Not so much ouch and still cheaper than the old Depron Pricing.

DTF is 20" x 30" not 48" x 24" so there is a slight difference in material area.
Not to mention it's paper covered.
when that starts to absorb moisture and delaminate ... bye bye model :>{

Otherwise it Sounds like there might be some $ to be made slicing Dow. :>}

However, when doing your business plan, I would make allowance for some Thinning due to the Hotwire Melt-away/Kerf.
Then there is the Labor time and machine cost and other overhead for the slicer.

Regardless I'd buy a box of Blue foam !
Last edited by birdofplay; Aug 14, 2017 at 11:13 AM.
Aug 14, 2017, 12:45 PM
treefinder
springer's Avatar
I've been following this thread since it started, and been wanting to chime in, but just as I'm ready to post, another of my satisfied customers posts and answers the question before me! (I like that!). But just to clarify a few items: first, the MPF foam itself is the same recipe as the latest Dow HighPerf LF fanfold foam, but without the colorant, film, printing, perforations etc. so it has what many feel is the best balance of performance characteristics - Less brittle, therefore tougher and more damage resistant than Depron but less stiff than Depron. Stiffer and tougher than DTF/Readiboard and HK foams. It is extruded and expanded to it's final thickness, not slit from thicker stock, therefore has closed cell skins on each surface, versus paperless DTF which has broken cells on the surface when paper is removed. (that's why it tends to be more dentable than other foams) MPF is not as perfectly flat as Depron was in the past, but then Depron isn't perfectly flat anymore either and typically goes for twice the price per sq in (I use square inch basis because Depron is 27"x 39" (typically) and MPF is 24x48" nominal). Relative to wire cutting a sheet of thicker 4'x8' foam boards, I've not tried it, but would be concerned that I might not be able to keep out thickness waves as the wire cuts. Also, that foam, when I've used it tends to be less dense and more friable, though the wire cut skin may restore stiffness and toughness, so it may be an option if one is willing to go through the work.

As Bob mentioned MPF is about $4.40/sheet in a 16 sheet box shipped by USPS priority mail to most of the US. Unfortunately priority mail gets crazy expensive to the west coast and parts of the east coast and far south, so I switch to UPS/FedEx, and (in order to avoid a $11 "excess handling" charge for boxes over 48" long) trim 1 inch off the ends and rework the boxes to reduce shipping rates. in that shipping mode postage per box runs between $25 and $40. Actual will depend on your state. Also unfortunately, since both 8 and 16 sheet boxes are shipped using dimensional weight rules, they ship as 20lb boxes instead of the 6 or 9lb actual weight. That means that an 8 sheet box costs the same as 16 sheet box to ship. Not my idea or what I'd like, but that's the way it is.

Finally, RCJD, if you like I would be happy to mail you a sample pack of a couple of 10x14" sheets for you to get the feel of the foam and how it works. Just pm me a mailing address. That goes for anyone else who is interested but not sure if they want to pop for the $ for an unknown product.
Last edited by springer; Aug 14, 2017 at 01:19 PM.
Aug 14, 2017, 01:33 PM
treefinder
springer's Avatar

!


Quote:
Originally Posted by Bare
That's primarily because You use it in your "basement" business cutting Flat foamy bits for resale .
Why? someone would even want precut depron (or facsimile) model parts simply boggles My imagination.
But Hey ! a buck is where you find it.
MPF is actually XPS sliced into Depron thicknesses.

IF one was Cheap and didn't want to pay shippings... a Hot wire, a couple of thickness jigs and some DOW foam (USA made :-) would make for a very good alternate. Add in a #11 exacto blade and instant Kit
Hey! whatever floats yer boat.
Got a chuckle out of this one! When I first got into the OneSheet thing and did the OSG, I simply posted a dimensioned drawing on the thread as everything was straight lines and most full inch increments. Almost immediately, I got requests for templates! So, Ok, fine, I posted the PDF with templates. That was ok through several more OneSheeters, but when the builds got more complex and part shapes also more complex, folk commented "wish we could get a kit". So I found a local laser engraver who worked with me figuring out settings for foam and started onesheetkits.us. I don't sell very many kits, but the few guys who don't want to cut all the parts (70+ on some builds) seem to appreciate it. The thing I'm amazed at is how many folk buy profile foamie kits, which is mostly what I see in the LHS. 6-7 parts mostly straight lines. . . . I think Bob provides a valuable service in both cutting complex kits for existing planes and custom cutting planes for anyone who ships him a file. I consider myself a pretty accurate hand foam cutter with straight edge and Xacto, but now have my laser gal cut my prototypes, as there's nothing like the way the pieces fit together and how Rt and Lt parts are exactly alike! I would use Bob's service, but Yvonne is closer and cuter and just as fun to work with! Bob is a great guy, does great work and I appreciate him campaigning for MPF!
Aug 14, 2017, 01:36 PM
Hot glue held together by foam
balsa or carbon's Avatar
Quote:
Originally Posted by RCJD
Basically, once I did a complete cost breakdown, here are my results:

MPF: great foam, full box of grade A ends up about $70 including shipping, which makes it close to $9 a sheet. Ouch!

DTF: decent foam, half the thickness I need, so I would have to double it up, which makes it $2 per usable sheet.

DOW blue foam: slice 4x8x0.75 sheet ($15 at local lowes) into 12 2x4x0.25 sheets. Ends up $1.25 per sheet

HK xps, when you count in shipping, it costs the same as the DOW, for an inferior foam.

I'm thinking rigging a hot wire to cut DOW is my best option.
Unfortunately , DOW blue foam is not available everywhere ( like here in Portland Oregon ) .
Aug 14, 2017, 01:51 PM
treefinder
springer's Avatar
Quote:
Originally Posted by balsa or carbon
Unfortunately , DOW blue foam is not available everywhere ( like here in Portland Oregon ) .
There is that..., and It's no longer the $30/25 sheet bundle when one can get it. The last one I bought (before MPF became my go to foam - I have to walk all the way out to the barn to get it! ) cost $55 and another several bucks of gas money to pick up from Allied Products.
Aug 14, 2017, 01:52 PM
Retired CAD guy
birdofplay's Avatar
I noticed that also When I lived in Cathlamet, WA

I had to drive to Beaverton to find a Lows with fanfold !?!?!

I always figured that the OC plant in Troutdale had something to do with the ascents of DOW.

Springer: Thanx for Support and Comps


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