TDI vs MDI - the shit hits the fan!

 am bringing this debate over from the Sonic Foam thread because that thread was hijacked (yes Louise, this sometimes happens), and it really isn’t the proper place for someone looking for information later on to find the merit of the discussion, or more likely debate.

TDI= Toulene Di Isocynate

MDI= Methyl Phenol Di Isocynate

When ave you most likely used a isocynate other than blanks? Probably if you broke something and got out the Super glue.

Whereas there is huge and diverse use for isocynates, let’s keep it simple for starters and say that the debate involves the merits of MDI being more environmentally friendly than the big bad TDI that is purportedly killing all of us.

In the Sonic thread it is stated by an experienced shaped I know that TDI is killing all of us in the industry. I find that very interesting knowing that the statement was made by a fellow shaper (and now owner launching his new MDI, soy based blank company after earlier launching Homeblown Foam). Now this shaper has shaped thousands and thousands of TDI blanks, like myself, Terry Martin, Al Merrick, Rusty, Linden, Robert August, Greg Noll, Hap Jacobs, Wayne Rich, Yater, Bing, Brewer, Mike Daniel, Stretch, Steve Coletta, Glem Minami, Barnfield, Bruce Jones…well, you get the point.

Yeah, gazillions of TDI blanks, and guess what? We are still around. Do I have respiratory problems or am I shaping from a wheel chair with an oxygen tank?


Okay, so I hear about how great MDI technology is for the planet and the merits of the foam, and I’m open minded, so I get some soy based foam, I get some Cane foam, I put my hard earned money down on foam that my customers are relying upon ME to provide them the best possible product.

Well, to make a long story short…don’t worry, I promise there will be many other storiesfrom others on this thread to read…I’M NOT BUYING IT!


I do not believe MDI foam is as good as TDI based foam, and now any of you out there professing that it is will have to PROVE IT to me and quite a few others. The best results I had was with the Cane based from Ice 9, and some of the results were actually good. BUT, I also had some yellowing that I could not conclusively pin down to it being cane. The foam seemed to be less consistent than ‘good ol’ Clark Foam (TDI), and it didn’t hold a candle to the Walker Ice 9 Mowses foam…not for shaping and the strength to weight ratio of the Ice 9 Mowses kicked ass all over the Cane and Homeblown MDI foams.

So I guess the claims and postulating, ponitificating, and general gesturing will begin soon enough, but if I were advising a newbie what to do regarding foam, I would say this:

"Use an established blank company. Who? Someone who has been around consistently since Clark’s closure. Someone with a track record. Walker went to Ice 9 and they created Mowses…great foam…easy to shape, really good strength to weight ratio. Surfblanks. Midget Farrelly has been providing foam in Austrailia for decades…okay so Andrew is doing it here and the factory i south of Ensenada…big deal, good foam with lots of blank availability.

I don’t mean to slight other people that Greg Loehr or some others might suggest, but these are the folks that I have used and can honestly recommend. I won’t get into the EPS story here other than to say there are some very good suppliers and I will be submiting some utility blank designs to White Hot in the near future. So I guess that means I must feel EPS has a lace in the industry. Stretch knows where I’m coming from on that one.

But this thread is about TDI vs MDI, and so I just want to finish by saying that I personally do not give a flying shit that the foams I suggested above are TDI…they are BETTER THAN ANY MDI that I have used. Unless someone can prove to me otherwise, that’s my story and I’m sticking to it.


This isn’t spell checked, but you get the picture.


NOw I don’t know what happened but my original post jacked a whole paragraph that should have included U.S. Blanks…should have read

Lots of the Clark people went over to U.S. blanks. A partner in the company is Ted Wilson, owner of Fiberglass Hawaii, and a major materials supplier in the industry for decades. I was told that he supplied Burford (or perhaps it was Bennett) for years with materials to blow their foam. Like Surfblanks, they have great selection, good availability, and fair prices. After spending a fair amount of dough, I’ve concluded that MDI dents easier than TDI, ends up heavier after glassing, has less consistent performance overall than high grade TDI based blanks, and represents less overall value.

If you wish to dabble in many different types of foams, have at it. If you are on a budget or have customers you do not want to disappoint, stick with TDI and avoid MDI’s like the plague.

So in a nutshell"

Mowses, Surfblanks, U.S. Blanks

EPS option: White Hot, Austin (and other reputable EPS suppliers, not crap from Lowes or Home Depot).

…well, I’m off to go shape some TDI foam, I’m sure there are at least a few reading this that hope I die from it…sorry to disappoint.

Unless someone can prove to me otherwise, this is my story, and I’m sticking to it. There may be no chemically sound reason even a graduate of M.I.T. might be able to offer why MDI appears inferior to TDI…but until I am shown otherwise my buck will stop here.

Every MDI blank I used had a defect!

whoa now!

I'll take the TDI please! I don't want another can of whoop ass opened!

I think you might be referring to is fashion. Doesn’t matter how good the value for money is so long as the ads are “cool” and the product keeps moving. It’s what fashion tends to be about.

Totally agree,

the only advantages of MDI over TDI I could ever see is,

MDI is about 60% of the cost of a TDI to buy ,

and in theory (I dont do this)

MDI seems to have the same consistancy of foam density/strength thoughout the whole blank,
So you could shape a odd board from a wrong blank, i.e. a very thin board from a very thick blank you needed in a hurry
that you had lying around, without too much worry about hacking heaps of meat from the deck.

Otherwise, Stick to the experts, Bennet, Farrely etc in OZ,

Oh man, look at barry bennet, he has been mixed up in these chemicals for what seems like centuries and he is still kicken.

Of course I  should be even MORE dead than I am…being a glasser  a good portion of 4 decades and all the rest. Even fin panels…I should be deader than a door nail!


What IS a door nail?

You guys sound like a bunch of addicts who just can’t kick the TDI. Gotta have it!

I look forward to responding to all this jimbo jumbo when I get my hands on a keyboard.

Let me just ask one question so I can get this straight. Have any of you shaped Homeblown’s MDI in the past 18 months? If so where did you get it? Was it like a monster that still gives you nightmares? Did this monster eat all your resins? Did it crush your grandma when it fell over on her? Did it sink in the water? :wink:

I’ll see you soon


   you come on here with 6 posts & then you start puting everyone in there place?

just how many do you think you are going to get onside with that tactic.

i for one have a bad memory of bieng promised a far superior blank only to have more than 50 surfboards that  i replaced no thanks to the foam man.

but because i valued my customers      so my reward was to shape  glass sand finish 50 surfboards for free in my spare time  haa.


     so do you think in these times you can just walk in & demand everyone to jump

green  here is green      salvaged timber after a cyclone striped out &air dryed machined by me  no need for middle man at all

**[img_assist|nid=1045365|title=beech &; ceder|desc=|link=none|align=left|width=640|height=480]

I would like to see a non biased chemist break it down. Then have one of the super smarties show how a sporting goods toy is good for the earth. I mean really surfers surfing, driving and flying all over the creation to slide around on water…please. Stay home, plant a garden, turn off the power, and bathe in a stream.

If you were stupid enough to believe that your selfish pastime is making the world a better place by riding a toxic disk made with chemicals that would kill you if you drank them, then who are you fooling?

I agree lets be real. The TDI is the best, MDI is hassles, shrinking, swelling, temperature sensitive, etc. no thanks.

2 days, 6 posts
In that short time you have managed to slate all your competitiors, spread rumours that  one of them is closing,
made extravagant claims about your blanks,with not one shred of evidence to back it up, and then proceeded to tell all
the experienced shapers on here what they should be making their boards with, and how they should be making them.
Then to cap to all you accuse people who are obviously very experienced board makers, who have direct experience  of
MDI blanks, that they are all talking “jimbo jumbo”

That’s a pretty unique marketing strategy you got going there. I wonder how well it will work out.

used MDI lately? well 9 months ago i have… it turned brown as poo in 4 weeks sun. was softer than toilet paper and died from stringer rot in 5 weeks and about 15 surfs… now its landfill (not so green as a board that last for years) oh lucky it was free from a rep… i wasted 200 bucks glassing, sanding and finishing it!

Ned,(**edit: Now we know it is RYan, but this still happened and is relative noetheless) **I know you are very passionate about preserving our environment. I also am well aware that you are an experienced shaper, and an  intelligent and articulate human being that I have engaged in enjoyable dialogue with.

To provide a bit of history for the folks posting, I want to remind you that when I first met you and you were putting a lot of effort into promoting Homeblown, that I contacted you with an opportunity for us to combine efforts for a good cause here in Santa Barbara. That was a fundraiser for the S.B. Maritime Museum’s exhibit on the History of Santa Barbara Surfing.

You supplied the blank, and I offered to shape the Homeblown blank custom to the highest bidder winning the Silent Auction held the night of the gala, auction, entertainment, and surf movie. I raised $1,000 that night toward the fundraising event, which was about 1/20th (5%) of what the auctioned items fetched. Your Homeblown blank was promoted as a safer, more environmentally friendly product, and people attending bid on that basis and upon the basis of MY reputation in a town that I was born and raised and have considerable credibility.

While it is true that I have not shaped any of the (new) product that you are currently producing, it is also true that I had some problems with at least one of the half dozen or so Homeblown blanks I shaped. When I contacted you and explained the problem of gassing and a large bubble on the front(bottom) third of a Homeblown longboard blank, you told me a “cheater coat will resolve that”.

Not only did a cheater coat not resolve it, The bubble happened after I glassed the board (incl. a cheater coat before laying up), stripped the cloth applied a second cheater coat, glassed, re-hotcoated and let it cure. Then it bubbled again in the same place when allowed ot sit in sun for about 10 minutes. The board was a light yellow. THEN after stripping the area once more, I removed the previous material AND TRIED BONDO AS A BARRIER LAYER.

Even Bondo with glass failed with the same result. I ate that board, and I decided that was pretty much the end of my association with Homeblown Foam.

By nature, I’m not a masochist, although your take on anyone using TDI may debate that. I just don’t see how ruining my reputation with customers by producing a product out of substandard and/or UNRELIABLE material, can possibly benefit any of us?

Perhaps you have worked through some of the gliches that apparently exist with the MDI approach. As I previously stated, if an impartial  chemist can state definitive facts about the differences between using a TDI and MDI approach, then I am all ears. Of course those statements would be in theory and the rletative concern for those of making the boards is what happens in application of those theories and what it entails to work with the material, and if it holds up for the consumer.

Perhaps I will disgust you by stating that I can easily rationalize using some TDI blanks knowing that I do my part for a better environment by actively recycling, judicious use and disposal of the surfboard materials I use and their waste, have solar panels heating my pool, and have an orchard and garden of naturally grown fruits and vegetables.

Since I have my worksite on my property, I do not COMMUTE to work every day, thereby contributing less of a carbon footprint than most the people I know.

I personally applaud your effort toward building an environmentally responsible product. I do not approve of your shameful display on this thread. You are better than that and I know it. But it now appears that you have dug a hole for yourself by poor choices in words and no amount of proof will supplant what you have sown.

Start over, stick to the facts, don’t accuse, expect to be compared and criticized, then pick yourself up as a stronger person and move on with your convictions. We learn from our mistakes not from our victories.

I had no personal joy in relating my early experience with Homeblown. You guys were great, and I was hopeful the relationship would be mutually beneficial for each of us. It didn’t work out that way. Had you not responded the way you did on this thread, I never would have said anything to anyone. One bad experience doesn’t justify me bad rapping a young company trying to build good product. The other blanks I used netted a strong product and even the problem board is quite strong. However, contrary to the original claims, the strength to weight ratio was nothing to write home about, it was pretty much on a par with  others.

If you actually SPOKE with the Ice Nine guys, they would tell you I deal with them with my cards face up for ALL to see (and read) on this forum. The same goes for anyone else I deal with as I am small potatoes in this industry of ours and have no need for hidden agendas. That is how I live my life with the integrity my parents instilled in me. You are only as good as your word.

You reap what you sow.


…not spell checked…good night.

You guys sound like a bunch of addicts who just can't kick the TDI. Gotta have it! I look forward to responding to all this jimbo jumbo when I get my hands on a keyboard

JIMBO JUMBO? MDI is great for yellow boards with shrinking rails and pukas. 

Case #1. Sent 5 sample boards by jet to the east coast for approval to start distrubution. I Even had a experienced Channel Island Glasser do a retail finish. They looked great when they left. After 5 day they opened the boxes only to find the foam srank below the stringer top and bottom of the board. It also yellowed? As a result I lost the account 40 boards a month. Not a lot of boards however a good start with a company with several stores. I used the green card for my speal. No more green lies!

Case #2. Milled a rack of boards on a Monday. Came back Tuesday morning only to find every board with collapsed rails. Had to redo the whole order.

Case #3. Had an order for Peru. 15 boards. 10 MDI 5 TDI. All 10 of the MDI shrank on the plane down to South America. This destroyed a relationship with my customer that has never been corrected.

Case #4. Made a Tow board that turned yellow before the customer even picked it up. I did not have the heart to give it to him so I made another one using TDI and suplied it a week latter than scheduled. I hate being late!

Case #5. #6. #7. #8. I won't bore you with all the failures I experienced with MDI. Heavy, Yellow, Pukas, Shrinkage!

Trust me I not only loss Money, Customers, Friends but it just hurt my business. So I stopped all together using it regardless of all the Hype about how green it is! Come to find out it's pretty bad for you too. So wear a mask when you shape with it just like you do with TDI!

Hopefully you were just drunk when you wrote your rant?

I'm nobody so it doesn't matter anyway what I have to say.

Try and be more honest and realy look into MDI if it's is really green or not? I doubt it very much!

Give some to your cat!

Good Luck!


Huie I lost a lot of money as well with the so called Greener MDI!

Worked on a 10'0 Balsa this morning. So am I evil for using plant life?

Have a few TDI boards to do so I guess I'm a JiMBO JuMBLE shaper?

I make a lot of EPS/Epoxy boards these day so I guess I have more than one addiction?

Was it like a monster that still gives you nightmares?

Kind of like the first time I saw Frankinstein!

Did this monster eat all your resins?

No it drank it!

Did it crush your grandma when it fell over on her?

No she died from micro-waving gravy with MDI!

Did it sink in the water?

No but it killed the fish!

[quote="$1"] "I had some problems with at least one of the half dozen or so Homeblown blanks I shaped". [/quote]

What happened with the other 5?  How did they turn out?  Same problems?

“What happened with the other 5?”

The other blanks worked out without problems other than one yellowed in an inconsistent pattern on one side of the board. I correctd this by misting white on the sand coat. Lucky me, more work for saving the environment…?

However, I don’t accept a 15-20% failure rate. That figure will put me out of business!

I guess I am supposed to accept a less than perfect foam if it isn’t so heavy that it will kill grandma if it falls on her…problem is, will the blank manufacurer PAY for her hip replacement? Will the blank manufacturer subsidize my loss of business when the customer says “yeah I was stoked to get one of his boards but it was heavy and didn’t paddle that good”…? And so on.

Do I get a discount off the list price of this “greener” type of foam because it YELLOWS thereby requiring me to spray the shaped blank WHITE before glassing a CLEAR board order? Uh, even Homeblown originally stated they could color their foam that was “STRAW” colored but that involved increased cost. Now, if you dig straw, there isn’t a problem regarding color…I wonder how many surfers out there want straw, or perhaps I should shape ALL my orders out of MDI and leave it out in the sun for days before glassing it…I can start a new concept called “Pre Aging”.

Maybe I should offer my product line “Pre Dinged” too.

“No longer do you need to worry about that first ding you will inevitably get, because we can do it FOR you”!


The maze that was left for shapers to navigate in the wake of Clark’s closure, has pushed at least one highly regarded designer shaper to exclusively use EPS…that same individual was voted “Shaper of the Year” awhile back.

If someone’s foam has improved dramatically from what it was 18 months ago, and they are serious about being in the blank manufacturing business in this current economic downturn,they would be well advised to have a vast amount of seed capital in their quest to capture the necessary market share (in order) to make their venture worthwhile.

LEAN MANUFACTURING is the new buzz word for Sway’s this month. Learn about it, practice it, spread the concept and help others embrace it: this will help our environment more than all the psuedo green propaganda being shoveled over to young impressionable minds that will inherit this earth.

Ideology is exactly that: a manner of thinking in society in which one embraces theory or a combination of theories.

Theory: a belief of ideal or hypothetical facts, principles or circumstances.


Prove it!

The difference between selling me an MDI based blank and a 20 year old wannabe is appreciable. In my book the jury is still waaaay out on MDI. You guys are still in the proving stage. As shapers, we theorize then have to go about proving something too. I wonder what Mike Croteau would say from Heaven if he were asked?

“Yeah, almost everyone thought i was nutz putting 4 fins and multiple concaves on boards back then”.

No one is laughing now.

So go for it…prove your theory and make us all believers. But the only way you are going to get me to change my postion is give me a blank to shape and glass and test…and that is a pretty smart thing to do given that I don’t have an agenda like so many other people in the industry, I could give a flying crap which blank manufacturer gets ticked if your foam is (now) as good as you claim.

Competition is good, I’m doing YOU a favor by being willing to even try it, otherwise you’re just selling me Jimbo Jumble.


I know be polite, be helpful, but "jimbo Jumbo" that is a crack up.  I'm going to start calling everything that bugs me that I can't control it's outcome of "jimbo jumbo".

Example:  "Man it is so jimbo jumbo today.  How come it's raining." or "Shucks the waves are jimbo jumbo.  It was much better earlier." 

Much much better than profanity.

Either that or this gentleman is secretly involved is this debaucle?  A mad chemist perhaps?

Sorry too much coffee in the morning makes me sassy.  Continue on please.

You guys are too funny- Great Humor!  Thanks for the info!