Mylar

[BeanAnimal]

What type of tolerances are we talkââ"šÂ¬Ã¢"žÂ¢en about here Bean? I would say that 99% of the projects here do not measure within those set by professional engineers or the precision of multi-million dollar lathes and fabricators.

Your are correct, but in this case it makes a HUGE difference. That is the entire point. Some things are great DIY candidates, others just not worth the trouble. I will also say it again, if you are trying to build a better reflector, save your time, you simply can't (with basic DIY skills and tools). If your just trying to have some fun and aware of the limitations, then go for it.

This is a DIY forum and its not necessarily the aim of those here to be that critical of performance. Itââ"šÂ¬Ã¢"žÂ¢s the tweaking, testing, implementation and for me the cost savings that bring me to DIY.

Firstly, a question was asked. I provided an answer. Secondly, the information provided was to steer the OP away from using the MYLAR. This helps to take an itteration out of the tweaking.

Thridy, with regards to cost savings... if the reflector wastes light, what are you saving? You could use a better reflector with a smaller bulb and save the money. A good look at Sanjays numbers will show you this very easily.

On Beanââ"šÂ¬Ã¢"žÂ¢s side however, getting more than 90% of the light to ââ"šÂ¬Ã‹Å“stayââ"šÂ¬Ã¢"žÂ¢ in the tank is exceptionally hard and companies have designed very specialized reflectors to attain that. My route took both things into account by using a reflector then mylar to reduce lost light (mainly reflected back off the water). My hood is almost totally enclosed therefore I probably am reaching 98 or more percent efficiency. By implementing both methods I have attained what I know are tangible results (tested by a light meter in a plastic bag ).

As I stated, your setup uses a decent reflector design and then gathers the light that bounces off the water or other objects and puts some of it back in the tank. Great idea and likely well worth your time and trouble.

Have a nice evening.

 

[dvanacker]

There is alot of engineering and tight tolerances when it comes to a good quality reflector. I agree with bean that it would be hard to reproduce this on a DIY scale.

If you fine with losing 10, 20 or 30 percent efficiency then go for it....but I highly doubt the regular DIY guy could replicate a lumenmax or lumenarc or whatever quality reflector without losing some efficiency.

 

[olemos]

<a href=showthread.php?s=&postid=7139646#post7139646 target=_blank>Originally posted</a> by dvanacker

but I highly doubt the regular DIY guy could replicate a lumenmax or lumenarc or whatever quality reflector without losing some efficiency.

By having the opportunity of making 3 DIY reflectors(altho I admit I used the wrong materials) I have to say that these would be one of the few DIY projects that will be as close to the original (by using a equivalent aluminum) as you will ever get,
as I said before the pieces will only interlock together one way.
if they don't fit together, you did something wrong.

 

[olemos]

Beananimal I always appreciate your input, that is what helps us get around some of the obstacles we encounter when trying these projects.
Pleas don't be discouraged from posting, by people sometimes not understanding your points to well.

 

[BeanAnimal]

I am not discouraged at all. I simply try to offer help when I can. If you can duplicate a reflectors exact shape then your only theoretical losses would be in your choice of reflective surfaces and precision in your work.

Bean

 

[olemos]

Bean, what are you thoughts on SolarTubes, as a choice of material for this project?

 

[BeanAnimal]

From evertyhing I have read, the SOLA brand skylight extension tubes have a great reflective coeficient. They are highly polished front coated material, that is designed to transmit a very wide spectrum of light very efficiently. Your biggest chore will be to make sure you do not distort the pieces during fabrication.

 

[fishbaiter]

Thanks reefnewbie..

Thanks reefnewbie..

Hey I want to thank you for the tip on the Mylar. Sounds exactly what I have been looking for for my custom hood! Sure beats spending loads of money on "scientifically proven" pieces of erquipment.

I am new to this forum but not new to the hobby. As we ALL know this hobby is not cheap and if we can save money by making or creating equipment ourselves than more power to us. Hence the reason for the DIY Forum... This is where you get suggestions not a place to have a debate. You give you opinion or thoughts and that should be it, shouldn't have to argue it!

So where can I obtain this Mylar at?

 

[MAreefer]

Any local grow store, make sure to get the real stuff not metallized polyester. I dont know any sites off the top of my head but if you google it I'm sure there are plenty

 

[BeanAnimal]

fishbaiter, either you didn't read and understand the thread, or you are simply trolling. In the case of the former, if you go back and re-read you should be easily able to come to the conclusion the mylar is a poor choice for a reflector for many reasons.

In the case if the later, I would suggest spending a little more time reading the forums instead of shooting your mouth of with your fist post. But then again my bet would be that your IP address would match one of the others aleady in this thread, childish to say the least.

 

[fishbaiter]

Hey Beaner, whould you just take a sedative. I heard what you said and others. But I choose to do it this way so with that said thanks for the "input" and that now should be it.

Thank you MAreefer, I do appreciate it. Mylar's the BEST solution! =)

 

[BeanAnimal]

Let me get this straight...

You start a thread asking for help (assuming fishbaiter and reefnewbie are the same person). You happen to get a very informed reply (actually several from more than 1 person) and isntead of saying thank you, you inform me (us) that our opinons were not wanted or needed and you wish to do things your own way? The conversation here has been polite and informative (with the exception of your own posts). In other words we have all tried to carry on an intelligent conversation in your presence.

Instead of saying "Thanks for the input, I understand what you guys are saying, but I think I will try the mylar anyway". You you create a new user account to troll for an arguement so that you can somehow prove you are correct? You want to somehow paint me as a rude or mean person?

Give me a break! Please do us ALL a favor, don't ask for any more help unless your willing to hold an adult conversation regarding the answers you receive. You may not wish to follow the advice given, that is your choice. Just remember that the information in these threads is read by hundreds of people, some who may be interested in the facts so that they can make informed decisions when deciding on the materials or methods for a given project. You asked a question and got good answers. You got more information than you may have wanted, but it was good information. Do with this information what you wish...

fishbaiter if your now the same person as reefnewbie, then you really are out of place in this thread and are doing nothing more than trolling.... but I don't have to tell you that, as you and everybody else can see it.

have a nice afternoon

 

[fishbaiter]

Enough Beaner! What is it with you and your infintile behavior? Fisrt off you proved you couldn't be more wrong by putting me and Reefnewbie in as the same person which now leads me to believe your OPINION on Mylar has serious questions. I couldn't finish reading your most recent remark. To much of a waste of time. I think I'd rather eat a borrito and have the runs.

I'm sure you have valid points but conciderd to other solutions and after hearing others opinions I will go with Mylar because in MY OPINION I feel it is the most viable solution.

I'm not going to bash you like you are bashing me. I'm not juvenile like that so Beany can continue of which I'm sure you will. But as for me I'm done with this thread

Thanks all for your input. In the future I will try to stay away from the same thread the Beaner is on because it is apparent that there is only one opinion in the thread that matters!

Have a great day, suppose to be a beatiful day here in the Chicagoland area, finally.

 

[BeanAnimal]

What does my opinion of who you are have to do with the properties of MYLAR or reflectors?

Since you insist you are an individual and not reefnewbie (my apologies to him if this is so), I wll address you as an individual.

If YOU wish to use MYLAR, nobody is stopping you. Actually nobody said anything to you. Instead you found the thread and jumped in out of the blue, offered YOUR opinion and put me down in the process.

You have a total of 3 posts here at RC and each and every one of them is confrontational. Amazing to say the least. This was a cordial thread with a host of good information. If you don't agree with any of the fact or debate here, then please add your opion in a polite manner. Be open to discussion, that is what the forum is for. You simply can't blow in the door (in somebody elses thread) and say [SIC] "everybody shut up, I have given my opinion and yours are no longer needed". Sir, that is exactly what you have done.

I am not quite sure what your problem is, but you seem to want to argue about something. Is it the properties of MYLAR? Is it about the way reflectors function? Is it tha cost of "scientifically proven" equipment? What exactly is your point, other than the fact that you live in a free country and can use Mylar on a DIY reflector if you so wish? You sure tossed in your own opinions while admonishing others for theirs. If your willing to discuss the pros and cons of the Mylar or reflector design, then feel free to add to this thread. If you simply wish to slam me for my opinion or the information I have added to this thread, then your certainly are out of place here and not contributing anything useful.

My input has been rather simple...

Mylar is neat stuff. It has many uses including reflecting light. It is very popular in greenhouses becuase it is cheap, easy to handle, cleans very easily and weighs very little. The mylar does not make a good primary reflector for many reasons, but mostly because it is hard to keep perfectly flat. The spectrum that it reflects well can also be a problem. However, as shown above it can be a great secondary reflector, putting otherwise wasted light into the tank.

Care should be taken selecting the glue and the type of mylar material. MH bulbs get very hot and a fire hazzard could be the result.

For a primary reflector, specular aluminum is much easier to keep flat and free of surface anomoles. The higher reflectivity and improved surface will contribute to a much higher overall efficiency.

As stated 2-3 times in this thread, knowing the limitations is the starting point. If the limitation fit within the goal of the project then all is well. On the other hand, if the goal is to build a reflector that is "as good" or "better" than a commerical unit, your barking up the wrong tree.

Reflector DESIGN as another issue all together, but be aware that it is VERY SCIENTIFIC. A sutdy of the numbers at Sanjay Yoshis website will help you to understand how drastic even small differences in reflectors can be. Reflector design as complex (or more so) then lens design. Anybody can bounce "some" light where they want it, however the amount of light is the key.

 

[fishbaiter]

Thank you, apology accepted....

 

[BeanAnimal]

http://shop.store.yahoo.com/77hydro-store/mylar.html


They have 2mil stuff that would be less prone to surface deformity.

You need to handle this stuff like you would tinfoil you are trying to keep smooth. Every time you bend it tiny microscopic cracks or fissures form in the metalized layer (it is tinfoil stuck to mylar film basically). Smoothing the material out will also cuase these cracks.

These tiny cracks will significantly reduce the reflectve properties.

In any case the best course of action would be to NOT glue it at all. (other than a border around the edges to hold it taught like a canvas on a frame). A vacuum press would also something to play with. You can find very simple plans at JOEWOODWORKER.COM A very thin layer of sprayed on glue may work with the thicker film.

The thinner films will telegraph the glue texture through and absolutely destroy the efficiency of the reflector.

I should have a PAR meter in the coming months and will play around with some different methods of trying to attach this stuff and compare it to specular aluminum... just for the purpose of not having to go through this again

 

[BeanAnimal]

<a href=showthread.php?s=&postid=7142653#post7142653 target=_blank>Originally posted</a> by fishbaiter
Thank you, apology accepted....

LOL... you kind of lost me here...


I did apologize to reefnewbie if I had mistakenly assumed that YOU (fishbaiter) and HE (reefnewbie54321) were the same person.

I did not apologize to YOU (fishbaiter) but rather, asked if we could get this thread back on track.

It appears however from your post, that you ARE reefnewbie and just blown your cover by posting from the wrong account (oops). In this case there is no need for an apology, as everything I said was indeed true! I guess on the bright side, you got cuaght on a fish forum and not an adult dating forum or telephone conversation with many girlfriends.

-OR-

You simply have no idea what I am talking about. Which is also fine, as long as we can keep this thread on track.

 

[rforrest3]

I came into this thread to get some information and that I did. What I didn't expect was a squirting contest. I think some people need to take a chill pill here. I'm sure if someone wants to try using mylar as a option it is ok. I think some of the reflectors out there that don't have the full circle coverage like the luminaracs do they don't do much good at all. By the way I use the $30.00 cheep ones. If someone can make a luminarac and use mylar they will get better light and more reflection than the ones I use.

As far as someone who has built all this DIY stuff for themselves I bet they didn't think about how the beer was gonna taste or how the speakers were going to sound versus the highly engineered store bought ones. I bet the skimmers made are not the same as highly engineered ones either, but then again lighting is all that is cared about here.

Please get back on track.

 

[BeanAnimal]

A few thoughts...

Of course there are reflectors out there that are junk. Most of the reflectors (and products) sold in this hobby are junk. That certainly is not the point here.

Adding your comments about a "squirting contest" only adds to the fray. The contents of the thread speak for itself. Yet you jump in here, add your admonishment and opinion, then strike out on the offensive yourself. Not until you are done spouting YOUR OPINIONS and personal attack do you then ask us to "please get back on track"? Time to look in the mirror sir, you have just joined the squirting contest. Good grief.

I do wish to answer your last paragraph (which is nothing more than a personal attack).


With regards to your analogy to my other DIY ventures :

I simply stated that if the limitations are known and the project has other worthwhile merits (enjoyment) then it is not a wasted project. I did point out the limitations of the MYLAR and DIY reflectors so that the OP and others could better determine the pros and cons of such an undertaking. The OP was looking for a money savings by building a unit that matched the performance of the OEM unit. I (and others) attempted to show why this will not be the case. You need to re-read this thread sir. This time try to read it in context of the original question.

With regards to the BEER making:
It costs me more per case than "store bought". It has a short shelf life. It sometimes does not turn out to well. It is a LOT of work and there is little reward, other than knowing I brewed it.
It is something I ENJOY doing and am under no dilusions that I am saving money or making a "better" product. I only hope to learn with each batch so that the next one is better or at least as good. I know the limitations and the merits of my project.

With regards to SPEAKER DESIGN:
I build speaker systems that sound BETTER than many "audiophile" systems costsing hundreds of thousands of dollars. I do this with very precise engineering of the design parameters and long hard hours tweaking the electronics. I can control the "compromises" that others have to make, as I am not doing this for profit. I can choose the drivers, components and materials to suit my needs. I use special tools and software to achieve my goals. I have spent most of my adult life learning about how the components of a speaker system work to make and shape sound. This includes everything from the type of voice coil or surround on the driver, to the type of capacitors used in the crossover, and the differences between a cubic centimeter or two of space or a gram or two of insulation. Constrained layer contruction techiniques, baffle shape and driver placement are also critical parts of the designs.

Likewise, a DIY reflector COULD be made using special software and tools.

What is the difference? COST. For $3,000 I can buy the tools and materials to build a set of speakers that rival anything on the high end market, saving myself thousand, it not tens of thousands of dollars on the sound I desire. Of course I have the skills to do the design and work. To buy the TOOLS and SOFTWARE (or books) to design an efficient reflector would cost much more than the price of a new reflector. SO therefore the only reward can be the satisfaction of DIY itself (which I have stated several times is perfectly valid, as long you you understand the limitations of your DIY reflector).

Skimmers are also a different story. There are plenty of DIY skimmers that rival or surpass the commercial units. Why? rather simple, the materials and techniques used to build skimmers are readily available to the average DIYer. There are no complex curves or shapes to calculate then bend or machine. There is no optimum focus area or other focus issues to deal with. Skimmers are rather simple devices. Their complex function is a result of simple parts. A reflector is a simple concept with very complex parameters that dictate it's efficiency. A skimmer is easy to oversize, a reflector is hard to maximize.

Bean

 

[RichConley]

<a href=showthread.php?s=&postid=7139646#post7139646 target=_blank>Originally posted</a> by dvanacker
There is alot of engineering and tight tolerances when it comes to a good quality reflector. I agree with bean that it would be hard to reproduce this on a DIY scale.

I agree, the problem, is the assumption that most of these reflectors are good, quality reflectors. Yeah, the lumenarcs, lumenmaxs,etc, are pretty good. Most of the others are crap.

I'd bet money his DIY will spank spider reflectors, etc. The fact that a lot of these reflectors are open ended,etc speaks volumes as to how much "engineering" goes into these things.


FWIW, Mylar is extremely easy to get perfectly flat. Also bean, I have a hard time believing that an $89 reflector made out of a whole bunch of facets is being cut to very high specifications. Its just not expensive enough for the time and high quality equipment that would take. Theyre probably pretty well made, but there are tolerances there.