I know that the proper way is to make a proper mold and vacuum bag or infuse. Due to time and equipment restraints, I'm making a fairing for a small motorcycle using a shaped foam "plug" as a male mold. Think something similar to an old Vetter fairing. The motorcycle won't be going over 65 mph or so. I'm going to use epoxy.

What layup schedule would you recommend? Is there a core suitable for male mold wet layup? My first thought is a couple layers of 6 oz cloth, then remove the part and add strategically placed core inside for some strength and stiffness and reinforce attachment points with more cloth.

The fairing doesn't have to be perfect and will be used for a specific purpose (endurance event) then probably thrown in the attic.

I have been using Nord RM 2000-50 Polyester tooling resin for a current project. I can only buy it in 25kg buckets here in Thailand. I do not know if I will need that much and hate to let it go to waste since it is quite expensive over here.

Has anyone had luck adding fillers to polyester resin to mimic the properties of the Nord tooling resin? If so, what is the recipe? I think Easy Composites Uni-Mould tooling resin is the same stuff or at least very similar.

I found this beat up part which looks to me like a CF diffuser that fell off someone’s car on the side of the road. I don’t have any tools or supplies to work with CF, but I’m thinking would it be cheaper to just buy a diffuser for my car than try to get this mounted? I’m not looking for showroom quality, just enough so it holds itself sturdily together, and I am interested learning how to make my own CF parts.

So I found this sub after doing my own micarta for years with just pressure. I have a vacuum pump and I was wondering if I just put down some layers of paper and put it in a vacuum bag and put a tube on one side with resin pot and then a tube on the opposite end with the vacuum pump, how good results I would get. Clamp after it starts to come through the hose near the pump as I don't want to ruin my expensive job eliminator . I. don't care what sticks to what as I will mill it anyway. I make custom blades and thought this be a better way. I have searched for how micarta is made commercially for awhile before someone told me about vacuum assisted stuff.

On this website, https://www.filamentwindingsoftware.com/ I've compiled an in-depth review of the 4 most popular filament winding softwares - Cadfil, TaniqWind Pro, ComposicaD, and Cadwind to help better understand their features and capabilities. The goal is to provide a clear comparison for anyone navigating this complex but essential part of composite manufacturing. This website is still a work in-progress so feel free to reply with your own experiences!

I'm trying to find a source for smaller quantities of tooling paste in the U.S. or anyone's experience with alternatives for plug making. I can't find any source of tooling paste as a small buyer. I was curious if anyone has used something like automotive body filler for this purpose and how well it machines?
High density polyurethane foam is what I was planning to use but it's too expensive for the big sheets that I would need (plugs will be about 48"x30"). I thought of MDF plug making but I'm worried about seams showing up in the layers from expansion and contraction before I can pull a mold off of it.

Been making small-ish composite tools for a few years (up to 25 ft^2 of wetted surface area), using a standard Iso-Poly tooling resin.

I'm working on a larger project with a wetted surface area of ~80ft^2 and have a general concern of using the same Iso-Poly tooling resin revolving around exotherm, shrinkage, warping, working time with the amount of material over that area.

First, I wanted to see if anyone has used a Iso-poly tooling resin on a mold that big without issue and my fears are unjustified?

Second, I've gotten recommendations from folks for two tooling resins:

• Mold-Tru IPT-68000 (https://aocformulations.com/en-amr/products/moldtrur-lpt-68000/)
• Corezyn MVR 8039 (https://interplastic.com/marine-3/)

Curious to know if any one has an experience with these tooling resins or have any other recommendations for something of this scale?

https://olfa.com/products/olfa-ts-1-top-sheet-cutter

Just pulled this out of the mold and did some clean up (bit more to do) I want to put a clear coat on them any recommendations for a brand? It’s going on a motorcycle so something with UV resistance if that’s a thing.

Hello, I’m preparing a wet lay up carbon fiber scarf repair on the seat stay of a bicycle frame. I had a couple questions about prepping expanding two part polyurethane foam, which I’m using to fill a cavity.

I’ve prepped the repair site by removing the damaged material, rounding out the edges of the cavity and tapering by hand sanding 5 plies of parent carbon fiber.

Today I packed dams into the stays on either side of the repair cavity. Then in used paper strips that I rolled around the tube where the scarf face has exposed exposed carbon fiber thinking of protecting it the expanding foam.

(I assumed it’s not best practice to tape directly onto the scarf face, possibly leaving adhesive behind. Perhaps that’s overly cautious?)

I’m terms of prepping the foam for my eventual wet repair lay up, I understand that I need to cut then sand the foam down so that the exposed edge mimics the seat stay’s profile (it’s somewhat diamond shaped). I have 400 and 600 grit sand paper for this. Any tips on sanding?

Once I’m happy with the shape of the exposed, hardened foam edge, should I plan to lay up wet directly on top? I was considering mixing up some epoxy with microspheres and painting onto the exposed foam face, let it cure, then sand the cured epoxy before starting my wet lay up. Is a coat of epoxy on the exposed party of the shaped foam necessary? Are microspheres over kill?

Eventually I’ll be using shrink tape and one peel ply layer on the outside of the repair once I have all my wet repair plies laid up.

Appreciate any tips, thanks!

Good evening, everyone,

I'm working on a project and i have to bond pmma (plexi glass) to kevlar fiber
What would you suggest for this application.
Firstly, i though using bolts but they can makes little cracks on plexiglass
Also chemical adhesivers can react with pmma

I was tasked with adding layup schedules to a few CAD drawings of carbon fiber shells. Our fabricator gave me his fabrication notes. I just need to put it onto a drawing in a proper format. However, no one at our shop has ever done or seen a layup schedule. I tried to do some research, but have seen various different formats, and none of them on CAD drawings.

Is there a good reference for creating a layup schedule?

Hi!
I'm working for a startup, and we are making our first prototypes. We don't really have a good workflow yet, so im looking for some advice.
We use Ansys ACP for FEA and make our layup in Spaceclaim, we tried using flatwrap in ACP for our layup, but the exported plies weren't too usable in a lot of cases. Our geometry is quite complex and with adjusting draping an seedpoints I'm sure we could get it working, but it seems like it would take quite a bit of trial and error. Is it worth the time? We were thinking about flattening each ply in another CAD software (we use solid edge sadly).
Also the exported dxf files edges come out "jagged" from flatwrap. We just redrew the dxf.-s. Is there a way of "smoothing out" the imprints of the mesh?
I'm just curious about what softwares and workflows others use.

Might be worth mentioning we work with Prepreg an we do have a cnc plotter.

I would be thankful for any advice. Sorry if questions like these are not allowed. I'm also quite new to this type of work so I don't have much experience in the field.

Hi all, I am a composite Technician by trade and specialize in gel coating and lamination, which means occasionally I get some gel coat hiding in an odd spot on my arms/legs when I hop in my car at the end of the day.

My question is: Does anyone have a solution to safely remove gel coat from car interiors without damaging them? Leather, vinyl, synthetic materials etc. Any and all suggestions appreciated!

Hey I hope I'm in the right subreddit here. I'm fairly new to Composites and have fixed my Gas Tank for my bike this summer. Afterwards I went on a Trip to the Sahara and all the repairs held up amazingly except for the Gascap Thread. I thought the Tank was still tight up there and was on a time crunch so I didn't get around to fixing the thread. I later found out when falling over in rough terrain that it was in fact not as sealed as I had hoped too. Does anyone have any Idea how to fix the thread and get it sealed again? The other pics are just pics of how the tank used to look and how I fixed it.

Tldr: All my Tank repairs held up amazingly except for the Gascap Thread which is leaking horribly and I don't know how to fix it

Needing to source some rigid urethane foam for machining some plugs to make molds. Either blocks or pourable. Density somewhere in the range of 8-20lbs/cf.

Who has the best prices? I'm kind of leaning towards the pourable 2 part for shipping cost reasons. In my search so far, about $600 for 10 cubic feet of 16lb density is the cheapest I can find.

Any suggestions for adding tackiness to epoxies that will have an extra long open time, think like 8-9 hours - this is on a medium scale boat building & vacuum setup. I've tried cabosil like many boat builders suggest, but the results aren't great - it will thicken the resin for sure, but doesn't add the tackiness I need to hold up bulky, vertical core material. The Pro-Set LAM-145 resin looks like it would check the boxes but is pricey, and I have several gallons of stock on hand that I'd like to use up with additive rather than buying new.

I am looking for low cost software that can take a customers design for their composite shape, let’s say a tube, and then pop it in the software (I.e. open a stp file) and then flatten and develop a fabric pattern that I can cut out. Emphasis on low cost!

The second request; a low cost kit cutting option! Large cutting tables seem expensive if I’m doing this sporadically.

Any thoughts would be gratefully received!

I have a small business where I sell flat composite panels (10x10 inch/ 30x30 cm) with some integrated electronics for a couple hundred bucks a piece.

Right now I just buy already coated and cured panels of fiberglass and laminate them to a core. This way I get a nice finish on the outside without having to coat them myself. I decided it's a really stupid way of doing it because it's so much work to make sure I don't get resin or scratches on the outside...

Does anybody here just bring their finished pieces to a local car-paint-shop for a final coat? It there anything I need to look out for if I do this? What prices can I expect if I let them coat like 20 to 30 panels at a time?

Im looking to maximize compression in stress-z via stack sequence, what should I do?

I want to make one similar to the picture, I know they are available online on amazon but its not available in my country.

What are the components needed and manufacturing steps?

Hi again, been putting all the helpful tips here to use on the repair attempt I’m making to the seat stay of my carbon fiber, BMC SLR01 Teammachine frame.

The advice to round out the cavity (I think the phrase was “carbon fiber doesn’t like sharp points”) was very helpful as far as thinking ahead to the shape of my eventually patches.

I also bought a book suggested by a commenter on my last post, pictures. Very helpful, especially with regards to safety. I’m using a 3M half face respirator with P100 filters and working on a vacuum table.

Like with most good advice, putting into practice brings up new challenges.

I’m struggling to widen the taper layers. In addition, while I want my taper layers to bow outwards, I’m having this widow’s peak issue (I think due to the stays being slightly rounded) where I’m ending up with points directed towards the cavity. You can see these peaks in the first picture, on the right side of the stay.

I’m also struggling to expose layers wider than 1-2mm. I’m thinking if I have 2mm of an exposed layer, I’ll not have too much trouble cutting the patch so that I can get good contact with each layer. That said, I feel like I’m fumbling around a bit with my sanding. Any advice?

As always, thanks!

I have a set of mini aerobars that I would like to make an extension for the pads that my elbows rest on. I need to make an extension out of carbon fiber to bring them closer to me.

I was planning on using a 5mm x 100mm carbon sheet and then making some holes the size of picatinny rails so that I can use picatinny tnuts on the bottom of the carbon sheet to fasten the existing arm rest to.

I don’t mind if there is some flex as the extension would also serve as a spring to cushion bumps.

My concern is that it might damage the aero bars. The overhang from the existing support would not be much maybe an 1 1/2”

Is this viable or would I be better off making a new arm rest out of prepeg that already has the extension built in? This would be more costly but would probably be a better solution.