Blue foam is melting?

Yup, light coat on each side, let it dry a few second and then press together, this should hold it well, but be easy to sand. The white glue works great, but takes awhile to dry, the hot glue works good but you have to keep it in far from where you need to sand.

Second on the vinyl spackle, but if you want a matte finish anyway, you can lightly paint it with a latex spay paint directly…

I’d recommend stepping up to yellow foam though, it is worth it.

I agree, yellow foam is the way to go, you can get big blocks, and shape them down, much better than trying to glue layers of blue foam together, and MUCH faster to shape. If you have some money, renshape is the best.

I agree, yellow foam is the way to go, you can get big blocks, and shape them down, much better than trying to glue layers of blue foam together, and MUCH faster to shape. If you have some money, renshape is the best.

I agree, yellow foam is the way to go, you can get big blocks, and shape them down, much better than trying to glue layers of blue foam together, and MUCH faster to shape. If you have some money, renshape is the best.

Isn’t there a chemical difference between Super 77 and Super 78 -one eats foam and the other doesn’t?

Ah, blue foam models… and pink foam models… which evolve into yellow foam models… all those flavors still in my lungs after all these years!

Use ductape :smiling_imp:

Just look at the glue labels they all said you can use on foam or not. Never use super glue cause those melt. Woodglue or hobby glue all work but need a halfhour waiting time to wait till its dry.

Other wise use Muscle Pritt. Silver version of pritt superstrong and dry fast.

I was researching foam as a material for my modeling class and did a search and found this old post about foam and I keep reading about this “yellow foam” they talk about on here and don’t know what it is. So far, we have only worked in the cheap blue foam and Super 77, but we will be working in better materials soon, which I think is Balsa Foam. Is this yellow foam mentioned in this post, Balsa foam? is it the same thing? Just curious. is it harder, because I think I have touched it before here at school and its a lot denser and less brittle than the blue stuff we currently use. Is this it? Blick.com sells it in blocks.

Thanks guys

Super 77 is all you need. To be real clean tape the edges to prevent any deterioration at the edges for the crispest joint.

[u]http://www.freemansupply.com/RenShapeModelingan.htm[/u]

Renshape really is not workable by hand. At least not easily.

Ren is perfect for machining and doing appearance models, but yellow foam is a good in between. Dense, but still workable by hand, and usually you can find it in chunks that are several inches thick.

Super 77 will eat blue foam… get Super 78.

I heard Yellow Foam causes cancer. Supposedly, that’s why OSU got such a huge donation back when I was in school. Some company wanted to dump the stuff.

But I gotta say, it beats out every other modeling material I’ve used. Although clay was a lot of fun to try.

Hey guys,

Quick question. Do you guys use Bondo to glue layers of yellow foam together? My professor is advising us to use an alternative to Bondo, which I have always used. It seems to work well for me. Not sure what others use. She says Epoxy glues work better and are safer and less toxic than Bondo. What have you guys used in the past?

T’hanks!

Heya;

From my modeling past, I can agree that a modicum of Super77 can be most efficacious for gluing 2 pieces of blue-foam together…

(points for anyone who can tell me what movie that was in reference to)

Also, I agree with the epoxy to glue yellow foam together. The epoxy seam between the two will be harder to sand down as it will take longer to sand compared to the softer yellow foam. Use it sparingly, and don’t have it squirt out the edges of your seam and you’ll do fine.

I always used bondo for sculpting only - never as a gluing agent.

Take a look at why surfboard foam (White Foam) is no longer used…the specs get into your lungs and are shaped like little, jagged knives that cut your lung tissue every time to inhale and exhale…I used to know some surfboard-type people who practically bathed in it…no respirators at all.

And don’t get me started about not using Bondo with a respirator or using Methylene-Chloride for gluing ABS/styrene models together. Get some of that on your skin and it evaporates into your blood stream and heads for your CNS…

But - I loooovvvveed making models as a wee young designer!

Thanks for those tidbits about the epoxy use. I must try it out! My professor just wants to slowly wean us from over-using toxic products for modelmaking. I don’t blame her… as you said, we ID students (especially the younger ones…) tend to not think of the future and how certain toxic chemicals can do damage in the long run. When you are in your 20s, it seems it’s all about the here and now.

More than one professor of mine has mentioned how back when they were students, they didn’t use masks and breathed a lot of foam particles and Bondo fumes and now are suffering from adult asthma that they never had as children.

It’s scary.

Thanks again, East Coaster.

Well, as usual, I’m late to the party. I have 35 years of model, prototype, and production pattern making behind me starting in 1972.

Using any adhesive that “hardens” to bond foams “lifts” together is not a good idea. When you go to sculpt your form you will immediately discover that the hard adhesive does not cut at the same rate as the foam does and you will get a “ridge”. Fact is, the adhesive won’t cut at all, and you’ll end up picking it out and having to fill that craters… Spray adhesives are the item to use.

More importantly… PPE. Personal Protective Equipment should be worn anytime you’re in the shop. Safety glasses, respirator, and when using resins, adhesives, solvents, etc. NITRILE gloves should be worn. eastcoaster is 100% correct about the affects of methylene chloride (as well as; acetone, MEK, denatured alcohol, lacquer thinners, paint thinner, toluene, esters, and many others that designer/model-makers encounter); they all permeate the skin and target your central nervous system, kidneys, and liver … IMMEDIATELY. You should be wearing a respirator with an Organic filter cartridge, NOT a paper dust mask. A good one is about $40. The cartridges are replaceable (about every six months suggested), and the respirator itself will last four or five years. Maybe longer if you take care of it.

I’d even go so far as to say that when you lifting heavy materials, with sharp edges and/or splinters that leather gloves should be worn. It’s all a PITA, but you HAVE to do it.

I was/am still a religious user of PPE. But I can say from personal experience that the toxic affect of these materials on your body, twenty-five years from now, will occur. I started to develop hand tremors about five years ago, it has affected my ability to sketch, my signature, and my career. I operate heavy equipment now. I’m happy to hear that “educators” are finally starting to understand their full responsibilities to their students education. It extends way beyond just teaching them to “design”.

Read these past discussions … please. And take the information to heart. Download it, print it, and hand it out to your mates.

What are the best sanding and filling tools?

Urethane foam replacement
(Take special notice of the discussion about MSDS (Material Safety Data Sheet). It will tell you everything you need to know about a particular material (even water has an MSDS) to protect yourself. I’ll bet a buck that your instructor can’t tell you what MSDS means.)

LMO,

Thanks for that informative and cautionary, lesson-learning post. I am an older student in my 40s, so I am more aware of health issues and taking care of myself than most of my younger 20ish classmates. This week, I was doing an all nighter sitting in the lab scraping away at blue foam and I was wearing a respirator but some in that lab working alongside me were just wearing either paper dust masks or nothing at all! And some of those wearing no protection were sanding Urethane foam!! I guess when you are older, you are most of the time wiser and know that you can’t take your body and health for granted. These youngsters think they are invincible so hence why they don’t take precautions or worry about long term health.

Lmo, what did you mean by this sentence: “Using any adhesive that “hardens” to bond foams “lifts” together is not a good idea.” I re-read it a few times and didn’t get what you meant. I experimented with some “Gorilla Glue”, the amber-colored clear kind, at the suggestion of a classmate and it is so far bonding my thick layers of yellow foam well. I haven’t cut into it yet as I have it setting together and clamped, but I will let you know how it goes when I do. Hopefully I won’t have any problems.

Thanks Lmo.

CJS

what did you mean by this sentence: “Using any adhesive that “hardens” to bond foams “lifts” together is not a good idea.”

Sorry I wasn’t clear CJS…

By “hard(en)” I mean adhesives like epoxy, bondo (although it isn’t an “adhesive” per se), white/yellow glue, etc. When these adhesives cure they become physically harder than the foam… e.g. used on wood, it isn’t as noticeable because their “hardness” (durometer) is closer to that of the wood itself. Do a quick study for yourself (you probably already have) . Take two scrap chunks of foam and glue them together with yellow glue (epoxy would be much faster) allow it to cure, and then sand across the joint. You’ll notice how the foam doesn’t sand evenly when you cross over the joint. A PITA…

A “lift” is the term used for an elevation (a lamination in your case) … Originally, it’s a shipbuilding term.

The top drawing is “sections” also termed “traverses” , as viewed from either the front (right side of the drawing), or the rear (left side of the drawing); think of them as slices of bread. Only half each “section” is shown because a boat is symmetric about it’s center line; it saved time not to draw them. In the middle drawing the sections are located at each of the vertical lines starting at the bow (usually* position; “0”) In this drawing, for whatever reason, the sections number start at the stern. And, in this drawing the “sections” are labeled as “Body Plan”.

In the middle drawing labeled “Profile”, the “lifts” are the horizontal parallel lines,; they are also termed “water lines”. Because…? They’re parallel to … the water. I suppose the term “lift” comes from raising, or lifting, the line from the base line.

In the bottom drawing the lines represent the surface of the vessel at each “lift” as viewed from above. If you were to take a model of this boat and set it into a tank of water, and push it down, the lines would represent where the “water line” was at each elevation.

And just to make it a bit more confusing … also in the middle drawing, besides the profileof the hull, as viewed from the side, there are two other lines… labeled “buttocks”. Buttocks are basically just “sections” through the hull, but drawn parallel to the center line of the vessel. In the bottom drawing, they are represented by the two horizontal lines parallel to the center line. In the top drawing, they are represented by the two vertical lines that are parallel to the center line.
Developed around 1750, the 3d physical intersections of all these lines was calculated, by the marine architect, and recorded in a document known as the “Lines and Offsets”, which was used to assemble the vessel.

I was wearing a respirator but some in that lab working alongside me were just wearing either paper dust masks or nothing at all! And some of those wearing no protection were sanding Urethane foam!!

Dust masks (paper) are okay for dust… and I mean just okay. I’d absolutely wear something more, like the half-face respirator below.

In the picture below, the left side of the mask clearly shows the snap-on “dust filter” (white translucent) cover. More easily seen on the right side is the “organic cartridge” (black). Both are replaceable. The dust filter protects, and lengthens the life span, of the organic filter.

“Nothing at all” is completely unacceptable! Staff is remiss if they aren’t on top of this.

I don’t know what to say about your mates not wearing PPE. It’s very serious issue … for both the students and the university. If university staff is not aware of the long term health risks/issues of what they are teaching … they shouldn’t be teaching. Being “older”, you may be able to bend the ear of your instructor about the issue … or not. I would mention it if the opportunity arises.

LMO,

Actually, the professors mention it all the time, but there are no monitors in that modelling lab to advise the students to wear masks, so the students KNOW they should be wearing protection, but either they dont want to spend money on an expensive respirator mask or they are just stubborn.

Interestingly, when I first started at this school, 2 years ago, one professor, to my shock, mentioned during class that he felt respirators can be dangerous (I think he was referring to asthmatics and others with lung issues) and I felt that he was trying to prevent the school from being sued if a student suffers complications because of their use!! I don’t know how true that is, but I will keep wearing my respirator when sanding! If they are concerned about deaths/injury due to respirator use (which I find it hard to believe there are any) and also injury from breathing in particles when not wearing one, they can have students sign a waiver. I wouldn’t mind signing one.