| Author | Message | ||
     Lsr_Bbs |
I'll get it started, Joepitz said: Neil, I have used plaster of paris with shellac with good luck. But you can only pull one part with it. After that you run the risk of pulling plaster away with the part. If you want to go 10 cents more get one of the following products from a US Gypsum dealer: ULTRACAL 30 HYDROCAL A-11 HYDROCAL B-11 These products are designed to do just what you want them to do. These plasters do not shrink, something other plasters do. They dry very hard. Do not use drywall plaster. Anyone of the above any better/worse than the other? I used plaster-o-paris on the stuff I've done in the past, and your right on, worth one or two parts (if your lucky and heavy w/ the shellac). Any good pointers to books or websites on good techniques for laying up glass? Thinking this might be the way to go, the more I think about it...plus, once I get the skills worked out, I may try my hand w/ c/f. Neil Garretson X0.5 | ||
| Joepitz |
Neil, I have used B-11 alot and it works fine. The fact sheet recommends ULTRACAL 30 for tooling for epoxy. But ULTRACAL 30 may be more expensive. For books check-out www.westsystem.com. They have a free mag called Epoxyworks. Also Aircraft Spruce and Speciality sells some good books on composite technique. (aircraft home builders) Any boat building books are also good. But I can fill you in with enough info to get you started. If you are going to use paste wax as your mold release put at least 4 - 6 coats on your tool before you start glassing. About your tabs, You could use epoxy bonding techniques to bond tabs to your frame. You will have to strip the paint off in the location where you want to form a good mechnical bond surface. I have used epoxy and glass microballoons to bond to steel before (with glass and carbon) but there are alot of epoxy bonding systems that are so strong that the metal will break before the epoxy does. (I have not used these yet, But I have heard of alot of products that work well.) Check Aircraft Spruce, If I come across anything I will let you know. Got a meeting now I will follow-up later Tonight when I get home I will start posting some technique related messages to this topic. | ||
| Mikej |
Here's a link where you can spend some time wandering around the EAA web site. A lot of the home airplane builders get into all sorts of composites and panel buildups. | ||
| Aikigecko |
Styrofoam covered by a plastic trash bag makes a great form. As for kinds of glass unidirectional is sloppy but likely stronger for the purpose of fenders and the like than directional; if you want the fewest layers possible. It will need to be painted though. You can use directional in opposing layers and tint the epoxy with pigment for interesting effects. A bake oven will be needed for for each layer to achieve optimum results when curing. Epoxy likes heat the warmer it is (within reason) the better. We cooked snowboards at 300 degrees however that was a combination of both heat (an industrial blanket) and pressure (the press) but this can be as simple as a small sealed room and a heater or two. 110-120 degrees is all you really need...air it out before you re-enter though as there will likely be very little O2 left after a few hours. Another place to look for materials is the marine industry. My personal favorite is West Systems epoxy which is clear and therefore can be tinted but there are others.Surfboard epoxy can work but it can also be brittle if mixed to hot (best bet stay away from it). Epoxy paint is really fun and durable but again a heat room is necessary to get best results. Peace Tony | ||
| Joepitz |
First off I think we need a little introduction to get everyone on the same page. There are many resin systems out there, each one having different properties, cure times and cure temperatures. Two of the more popular resin systems out there are Polyester and Epoxy. There are several polyester resin systems formulated for different tasks, (Laminating resin, surface coat (sanding resin), hot coat resin and gel coat resin) The majority of surfboard construction is performed using polyester resin systems. There is Vinyl Ester Resin (simply put, share many of the properties of both polyester and epoxy resin systems) Vinyl Ester Resin is very popular in the marine industry. There are too many Epoxy resin systems to even mention. But I will cover the basics. Resin systems are usually formulated to meet specific requirements for the job at hand. For example: there are many room temperature cure resin systems, usually formulated for the wet lay-up process. (lay-up performed manually by hand, low tech tools, high labor costs) These resin systems allow plenty of time before the resin starts to cure (pot life) so laminators can wet-out multiple plies of fabric into the tool (mold) surface. These resin systems cure fully at room temperature, no oven cure is needed. There are other epoxy based Resin systems that need to be fully cured at temperatures as high as 350 degrees F. (We will get to those in a minute) Polyester and Vinyl Ester and many epoxy resin systems are often room temperature cure, hand lay-up resin systems. Polyester Pro’s and Cons Pro’s Polyester resin is very inexpensive Polyester resin is fairly easy to work with. Parts made with polyester resin can be gel coated. Con’s Polyester resin absorbs moisture (is not water proof) Polyester gives off styrene fumes, very toxic Polyester resin shrinks, parts will warp or will not hold original dimensions. Not as strong as epoxy. Epoxy Resin Pro’s and Con’s Pro’s Epoxy is much stronger than polyester resin. Epoxy does not shrink. Epoxy absorbs very little moisture. Epoxy fumes are toxic but fume much less than polyester. Con’s Epoxy is very expensive, more than twice as much as polyester. Epoxy in some cases has a very short pot life. Epoxy does not flow as well as polyester, harder to wet out fabric. You can pigment but you cannot gel-coat epoxy parts. More next message! | ||
| Joepitz |
Let’s continue I like to break down composite constructed parts into two categories: Structural parts and non-structural parts (cosmetic): Structural parts are those parts whose main purpose is to maintain major structural integrity of the part itself and are often designed to meet or exceed exact load bearing capacities. Appearance is a secondary concern. Non-structural or cosmetic parts are designed and constructed with more emphasis on appearance then on structural integrity. We are all familiar with cosmetic parts. Trendy carbon fiber fenders, tank protectors, trim strips and air boxes. Structural parts we all might be familiar with: Indy car or Formula 1 chassis and body-work, Sailboat masts, Carbon fiber brake pads or Kevlar brake lines. Tennis rackets and golf clubs. Space shuttle wing and wing spar components, F16 speed brakes and Kevlar bullet-proof vests. The primary reason I break down composite parts into these two categories is the following: Material requirements and construction technique. We will begin to cover these topics in the next message | ||
| Blackbuellm2 |
Joepitz - Great posts, you know you stuff. Two thoughts to add. (1) Shellac will only partially seal plasters. Best to follow up with 3 - 4 heavy coats of pastewax. Even then, depending on resin system selected, you may have trouble w/ part sticking to mold. (2) Again depending on the size of the part you are trying to model it may be prudent to use a thin set plaster for the face coat. The thinner a face the better it can transfer the cast. If the cast is of any size or weight hemp fibers are used for strengthening the cast. | ||
| Joepitz |
Thanks Todd for the feed back, I agree with you. Even after much wax I have still pulled plaster away with the part. I have also had good luck using a lacquer based surface sealer cut very thin with lacquer thinner. I brush on and wipe off many coats. Unless I am doing a quick one off part I still like to make epoxy tooling. In the long run it may take a bit more time but I get a much smoother tool surface that I can re-use. And don't smoke that hemp, they soak it in oil! ;-) | ||
| Lsr_Bbs |
Joepitz, thanks for all the good info, and pointers for getting started. How well does fiberglass hold up to high heat, say in comparison to c/f? For instance, as a heat shield on a header? Neil Garretson X0.5 | ||
| Joepitz |
Neil, It is not so much the fabric that matters with heat, unless you are designing parts for the space shuttle, then you would select a good ablative fabric. Carbon fiber when created is baked up to 1800 degrees F. Kevlar starts to melt around 1800 degrees F. and Glass is some where around the same temp. It is the resin system that you must worry about when fabricating parts for heat applications. Select a good resin that has a high glass transition temp (gt)(Point at which a polymer starts to breakdown.) The high temp Epoxy I mentioned the other day should work just fine. | ||
| Joepitz |
Let us now discuss what a composite is, what makes a good composite and some of the goals that you should have when making composite parts regardless of if the part is structural or just cosmetic. I will spare you the story of how the American Indians used clay and straw to make the first composite material called adobe. What is a Composite? A composite is a mixture of individual components that are formed together into a matrix. In most cases when these components are formed together the matrix of materials take on or exhibit completely different properties than that of the individual components themselves. This is a good thing! Let us bring this a bit closer to what we want to do, that is make cool looking composite parts for our Buell’s. Let us say we want to make a carbon fiber part for our Buell. In this case we have a composite part that consists of the following: A resin system, either polyester or Epoxy. Some fibrous material, carbon fiber, Kevlar or fiberglass. These fibrous materials can be formed into many different product types i.e. chopped strand mat, unidirectional or bi-directional woven cloth, chopper gun roving, or the latest fabric hybrids consisting of a mixture of Kevlar & carbon fiber. (We will get into fabric types in greater detail a bit later) And in some cases a core material, such as aluminum or nomex honeycomb, styrene or polyurethane foam or plain old balsa wood or plywood. Don’t laugh the latest model Corvettes are made of a fiberglass and balsa wood core. Balsa wood core is a very cool core material, it is light, adds good stiffness and is very cheap. The strongest part of this matrix is not the resin or core material. It is your fibrous material. The core adds stiffness not strength. The resin system is the weakest link. If you add too much resin to your part, your part will be weak and too heavy. The resin systems only purpose is to hold all of the other components together. That is all. Next section is: What makes a good composite and your fabrication goals: | ||
| Roc |
Joepitz - Thanks for the interesting information. Keep up the good work. | ||
| Aikigecko |
Just and addition to what Joepitz said about the resin. Resin as you know is usually a two part system (though there are one part systems that use things like UV light to cure them). Too much will indeed make your product weak and heavy (as well as taking forever to cure. Too much hardener will make the resin hot, both physically and chemically (yes I have been burned by glue before) as well as shorten your work time. This can damage both your core and the fibrous material you choose to wrap the core with. Interestingly enough the medical field has recently started using a two part superglue to repair cuts in hard to stitch area's. The glue is self cauterizing (it hurts like a M.F.) but the healing time is very quick. Anyone who has every rock climbed and has likely glued their fingers back together will know what this feels like. When working with resins follow the mixing directions very carefully and work fast | ||
| Joepitz |
One of my composites professors would always say that, “Talking about composites is talking about sex.” He would then proceed to elaborate on the topic of male parts and male or female tooling. When working with composite materials in order to create parts you start out with a bunch of raw materials that are at best very pliable, your resin system is a liquid. Your carbon fiber, Kevlar or fiberglass material drape like cloth and if used your core material is formable and not very ridged. The goal is to combine these materials into the shape of the part you are trying to create and hold them in place long enough for the matrix to fully cure. The best way to accomplish this task is to create tooling (molds) in the shape of the part you are trying to create. How you create tooling depends entirely on the following conditions: You want to duplicate a part that already exists and create a carbon fiber, Kevlar or fiberglass replica You want take an existing part and modify its appearance or size in order to meet some design requirement and then create a composite replica. The part you want to create does not exist and you would like to design and create a new composite part from this design. It would take an entire book on the subject of tooling to successfully address these situations. But I will very briefly discuss the first situation in an attempt to give you an introduction to tooling. Later on I will briefly discuss the other situations presented here. Let us say we would like to take the front fender off of our Buell and create a composite front fender made out of carbon fiber. Two of the more popular methods of duplicating an existing part are described below: Take your front fender off of your Buell. Create a wood box that will hold the fender in length and width and height. Place your fender centered in the box and fill in all of the gap space under the fender with modeling clay, (from the under side of the fender all the way to the base of the box. What you end up with is a solid shape of your fender in a box. Go out and get a hold of some of the plaster that was mentioned in one of the above messages. Mix the plaster according to the directions and pour the plaster into the box in order to completely cover the fender and clay. Let the plaster cure for the indicated time and then remove the fender and clay. Look inside of the solid plaster cast and you will see an exact copy of your fender except that it will be reversed from a male form into a female form. (Not magic just sex) You can now use this female tool to create a single male fender that you can then install on your Buell. (Not quite, but close enough for our example) (WARNING – Do not attempt to cast your fender at this time. Wait to read up on a more detailed version of tool making, I will go into greater detail later. If you do you will have to go out and buy yourself a new fender and you will be calling me some very bad names in the process) The other method of creating tooling from your existing fender involves: Take your fender and put it on a smooth flat surface. Fill in the gaps with modeling clay just as you did in the above example. Using the wet lay-up process lay-up multiple plies of resin and fiber material on top of the fender and clay. Repeat the process to build up a ridged covering over the fender and clay. Allow the lay-up to fully cure and remove the fender and clay. You will again see an exact female copy of your fender inside of the tool. There are many ways to create tooling for composites. I am trying to focus on the techniques that all us can do at home in our garages with simple tools and lots of labor. We now know a bit about composites, resin systems and tooling. We can now talk about fabrications goals and what makes a good composite part. | ||
| Aikigecko |
Joepitz, What do you use as a release agent on your molds so that your fabrication doesn't bond with them. Belive it or not we used PAM in the aluminum cassettes we laid up our snowboards in however that was metal and the press/cook time was short, though they cooled/cured for another 2-3 days before they were finished. Peace Tony | ||
| Joepitz |
Tony, I have used all kinds of paste wax, anything from good old Johnsons Paste wax all the way to high tech mold release paste wax. Wax work just fine but must be re-applied after each pull. You then get a wax build-up that must be cleaned off from time to time. I now use Zyvax semi-permanent mold release. You can get multiple pulls from it and I have used it on carbon fiber pre-pregs up to 350 Dregrees. It releases very well. By the way I have also had Johnsons Paste up to 350 Dregrees as well, and it works just fine. But putting 6 coats of wax on tooling each time is a pain in the you know what! | ||
| Vr1203 |
Help ,Is there a way to keep the paint from bubbling on the fuel tank? What causes that? I need a custom nonstock paint job. Is there a coating that will work? | ||
| Joepitz |
The tank on my Buell is plastic. When painting plastic you have to be real careful. You may have already done this, but you must clean the tank really well. No wax, grease, oil or gas. Because plastic is not a good surface for anything to stick to it you must provide a good mechnical surface for the paint to grap on to. Wet sand the surface, work down in grit, to 400. Go to your local auto paint store and pick up some surface clean and prep in order to really clean the surface. Also pick up some plastic prep. After tack ragging your tank spray the plastic prep according to the directions. The plastic prep provides a chemical bond surface for your base coat or primer to adhere to. Make sure you choose a good two part non-filled primer. (which means you have really to sand the tank so no imperfections are showing) Use a good two part Urethane, either PPG or House of Color. Ask the local dealer to give you pointers when spraying plastic. Hope this helps. | ||
| Vr1203 |
Thanks Joepitz That is more than I have got from Buell customer service(they said the bubbles behind the decals were caused by the plastic expanding and contracting while the decals could not causing the paint to buckle!!!),dealers and websites so far. Plastic prep ? | ||
| Roc |
I found this an interesting resource site for composite work: http://www.fibreglast.com/ | ||
| Gearloose |
I have two c/f tank accents that are now FOUR!!! They are cracked right in half vertically.A clean break and am wondering what to use to get them back together in original two parts.They will be painted afterwards.Would airplane epoxy and fiberglass mesh work on the backside.Any ideas? Thanks | ||
| Roc |
Gearloose - You are probably better off just buying new ones, depending on how they are broken. However - A local plastics shop, TAP Plastics in Portland Oregon, sells CF cloth and the correct resin for it. If there is a TAP by you it might be worth your time to go ask them. You might be able to get them back togeather with just resin, or maybe resin and CF cloth. CF sands very easy, but is itchy as hell and probably bad to breath. The like below contains pretty much everything I know about CF. http://www.bryanf.com/ | ||
| Ehjort |
Gentlemen, On my X1 lightning... One of my tabs that hold the tank Cover to the Air Cleaner Fairing broke. It broke right where the factory puts the tab onto the cover. Just wondering what I should do to get the pieces to stick together with a super strong bond without having to buy a Plastic welder. I have tried many glues, and non of them stick. I have even tried JB weld which is kinda like a cement. Nothing sticks. PLEASE HELP! Thanks again, Eric | ||
| Rocketman |
Eric, I've never tried it myself but you can purchase a carbon fiber repair kit. Demon Tweeks in the UK sell one. I don't know what's involved in broken of pieces but anything's worth a try. Rocket | ||
| Boogman |
hey joepitz, are you going to continue the lesson you started here ??? Im just about to start making my stuff and any more info would be great cheers boogman | ||
| Wyckedflesh |
Agreed Boogman, I just found this section and would totally love to learn more. Anyone know of any good DIY books on the subject that they could recommend for a novice? | ||
| Boogman |
I just started my project with good results ... essentially each time I have a go at this it gets better .. Making the molds from the originals out of gel coat (first layer) then one layer of fibreglass is where im at ... So far ive done the molds for chin fairing, fly screen and front wheel guard. Only the airbox cover to go .. With the chin fairing my idea is to eventually have a one piece unit that removes the need for the pop rivets ... essentially making the 3 pieces then glassing them together .. Best advice .... have patience, have all the things you need ready ... resin, glass matting cut etc.. AND ... have a go .. its not that difficult... but the resins really really stink .. so open air .. and face mask definately needed .. once Im done I will post some pics .. | ||
| Littlebuggles |
Looking forward to seeing your pics Brett, I'm gonna be fabbing up a new flyscreen when I have the cash to buy a new headlight. | ||
| Boogman |
No probs Mike... will post them ... gonna take a bit of time .. dont know what color ... and Ive also started my cheese grater removal .. good luck with your fabrication for the M2 ... a mate of mine has asked me to do something also for his M2 once im done with the XB .... regards brett | ||
| Boogman |
heres some pics of the glassing .. Turned out ok ...     | ||
| Ceejay |
Boog-looks good! I was wondering how you got from form to actual part. I have made a tail section for my tuber but am kinda stuck as to what would be the best way to go from the form to the part and was wondering how you started. Plus, if applicable what type resin as it looks like you painted your stuff...Thanks... | ||
| Boogman |
Cheers Ceejay ... Im happy with the result. To form the parts I made .. I used the original ... heres basically what i have been doing .. 1. apply releasing agent to original part.. I used a wax agent applied about 6 coats. Lots of buffing to make sure the entire surface is covered .. however there are many options. Best is PVC release agent .. ( sprays on light film and peels off ) 2. Apply Gel Coat ... let it completely set 3. Apply 1 layer of Fibreglass matting layed up wet .. using small patches to ensure all detail of curves etc are maintained. Smooth out the resin with a roller for no airbubbles etc ... for all edges allow for an overlap of dry Firbeglass matt .. and work the resin to approx 1/2 inch over the edge .. this helps with the handling and popping of the mold. let it completely set .. The mold shouldnt be too thick .. as it is easier to remove the part if there is flex in the mold. hence only one layer if matting is needed 4. Pop the mold .... with care use something like a plastic or wood lever to break the seal between the gelcoat and the original part. 5. Apply releasing agent to Gelcoat Surface .. 6 Coats of wax .. (or one coat of pva should be ok) 6. Apply 1 layer of Fibreglass matting layed up wet .. using small patches to ensure all detail of curves etc are maintained. Smooth out the resin with a roller for no airbubbles etc ... for all edges allow for an overlap of dry Firbeglass matt .. This allows for the final edges of the part to be taken back as required .. more to work with and cut back .. but better than missing a section on an edge .. ( i did that on the first part I made) Let the fibreglass completely set .. 7. Pop the part from the mold. with care use something like a plastic or wood lever to break the seal. Depending on the thickness of the part you want will depend on a few things. Fibreglass matting comes in various weights .. I would recommend not too thick .. as it makes it difficult to work with once wet with resin .. The lighter weight matting can then be applied with 2 / 3 layers just need to layup the wet glass over the top of the previous layer. Ive started a bit with Carbon Fibre also .. however out here in Australia its $50 a meter .. compared to Fibre matting .. $5 per meter .. but same process. the type of resin Ive been using is Polyester resin. there are a few others .. like ester resin (however the fume factor needs to be considered as ester is quite a nasty substance) then begins sanding & shape etc ... the Dremmel tool is awesome .. for the detail shaping etc ... Once the part is sanded and as smooth as I could get it with dry sandpaper .. One layer of primer putty .. then fill the imperfections with bondo .. ( mixed to a consistancy thats not solid like a paste .. but more like a thick paint) allow to dry .. sand with wet / dry .. then paint .. Any other questions or comments how I can improve what I do .. let me know .. There are a few forums that discuss fibreglassing techniques .. http://www.fibreglast.com/phpBB2/ They are much like here .. great info on how to and search the forum for topics before asking questions etc ... as per badweb .. Cheers Brett | ||
| Ceejay |
Right on Brett! Thanks for the info. Looking good. I have screwed around with Carbon fiber also, and it seems to come out a lot stiffer, but as you said, way more expensive.. | ||
| Boogman |
No probs CeeJay Yeah CF is alot let flex .. my next step maybe is to set up a vacume bag ... to use prepreg carbon .. so there is no foldlines in the finished product. Good luck with the fabricating .... lots of fun  Shame that doing this stuff doesnt pay to well .. Would be good to be able to make custom bits Problem is that the time it takes and price people would pay wouldnt be enough .. oh well ..  |
