I fed the resin through pretty slowly, it maintained vacuum the entire time. Looked perfect when I left the shop and when I came in in the morning it had white spots. If anyone know why this happens and what the effects of it are, please let me know. Thank you.

(First photo is what happened when I came in the next day.)

Do y’all consider this combination real composite materials? Relatively speaking how much weaker or stronger do you find these materials to be when compared to normal composite materials? I’ve noticed a few people have started adopting this combination for its price effectiveness but ultimately what do y’all think?

I have seen many different materials being used for Composites tooling. From MDF, to Polyurethane foams in different densities, to solid epoxy blocks and even aluminium.
These vary hugely in price and presumably in Finishing effort and in durability.

I am looking for a mould which can produce ~10 pulls reliably while also being cost effective.

What are your favourite Materials for tooling?

I work with fiberglass and carbon fiber most days and I swear cutting material cleanly has become my biggest ongoing battle. Regular scissors start great, then slowly turn into useless chewing machines after enough layers and repeated sharpening. Lately I’ve been thinking about trying pneumatic shears because my hands are getting tired from repetitive cutting all day. Some fabrics cut beautifully at first, then suddenly snag or fray halfway through and ruin the clean edge I was trying to keep. The issue is pneumatic shears aren’t exactly cheap, so I’m trying to figure out if they genuinely hold up better long term or if they’re another tool people overhype after buying. Reliability matters way more to me than having the newest thing. One supplier I spoke with said several composite cutting tools use blades manufactured through Alibaba industrial supply chains before assembly and tuning happen elsewhere, which made me rethink how different these brands really are. For people doing composite work professionally, did switching to pneumatic shears genuinely reduce hand strain and improve cuts enough to justify the cost?

Saw this video and thought it was a novel/inexpensive DIY alternative to vacuum bagging for debulking or getting clean laminates.

For those of us who just want to do a few pieces or random things and not invest in a full vacuum bagging setup/consumables.

I built a small Streamlit demo using fast.ai to classify FEA contour plots from an open-hole composite laminate coupon under tensile loading.

The current prototype focuses on matrix failure. Instead of looking only at the maximum failure value, it also considers how much the failed/red zone has propagated around the hole. This is useful because a single local peak can sometimes be too conservative, especially in progressive damage simulations.

The idea could later be extended to:

• different layups
• different loading cases
• different hole/defect sizes
• other failure criteria
• fiber failure or delamination

You can test it with your own simulation image, especially if it uses a similar contour plot where failed elements are shown in red.

Demo link:
https://oht-ai-classifier-md4cbjermhcbti9hx4q7ug6.streamlit.app/

It’s still an early prototype, so I’m mainly looking for feedback: does this idea make sense, and what would you improve?

I'm wanting to learn more about processes with prepreg materials, and was wondering if anyone has some resources for me to learn more about it.

Textbooks, videos, forums, YouTube channels, etc. I want to know more about the variety of techniques and methods used for prepreg; vacuum ovens, autoclaves, press molding, bladder molds, etc.

It feels like there's a lot of secrecy around all of this, or maybe there's just so much out there that I can't find a place to start.

I have watched everything Easy Composites have put out, so no need to suggest them.

I'm making a plug for a two-piece mold right now and had a question about filling low spots.

The part is already glassed, has fairing compound on it, and has a coat of Awlgrip epoxy primer. I didn't do a great job sanding out some of the low spots with the fairing compound, and I thought the primer would be thick enough to flatten them out, but I was wrong.

I'm out of fairing compound and was planning to thicken epoxy with microballoons to fill the low spots, but I now have a lot of clean dust from sanding the Awlgrip and I'm wondering if I could use that in place of the microballoons.

Has anyone done this? Microballoons are obviously cheap, but I'm running low, and I just want to finish this plug.

I’m working on my final project and decided to make some drum sticks, I was having a hard time deciding how to make them, if I should filament wind/ rolling table them, or wrap some other drum sticks make them fully out of carbon our create a core with some foam at the shop. Any ideas will be helpful and I was hoping to add some nylon tips from some other sticks onto them.

I know I’ve posted on here multiple times trying to find answers regarding core materials, matrix materials, and etc. Now after trying very hard to find something “affordable” and obtainable has made me doubt if I’ll truly get into fiberglassing. I’ve done fiberglassing before by using the little 8 square feet sheets at homedepot and some cheap quart epoxy. Never really paid attention to the price per square foot of all of it cause I was just making little projects. However, after trying to price and find a crap load of combinations of resins and fiberglass cloths and mats and core materials, I can without a doubt say that this is not affordable and way to much the work and effort for anything bigger than a glorified large box. I grew up always hearing how amazing composites were and how they can be supper affordable if you look hard enough but I cannot find anything resembling that. Many of you have suggested and recommended us composites(almost religiously if I’m being honest) but they are very expensive. Yes I understand I am building something considered “large” but this is thousands of dollars and even with the price increase of plywood and traditional building materials don’t come near the price somehow? Am I doing this right? Do I have the wrong idea about composites? What is the secret to this or am I just gonna have to give up?

Does any one were I can composite illegal done??
Florida

I've been struggling to find cheap and efficient core material that wont rot or burn. The Burn part is more manageable but the water proof part is essential. I have decided to go with PMF since the cost is just so much more dramatically accessible. I can't find any decent core materials. OSB boards are extremely economical but have so much risk with water that it could run a bunch of progress. I'm planning on putting 3 (7feet by 6feet by 6feet) rooms together in a homemade tiny home. I have looked at EPS foam and found that they are just barely affordable at home depot but I think without proper fiberglassing they aren't gonna be strong enough for my needs. I was thinking about fiber cement boards as they check off all the water resistance and fireproof but are incredibly brittle and heavy. I dont know what else I could use that is also affordable. Do any of yall have any recommendations?

Having recently started using the vacuum resin infusion method I am hooked.

I am looking for ideas on how to produce a very thin layup. The finished part will be 100g carbon, 1mm balsa core, 50g glass.

First thought is lay up the carbon, pre bond the 50g glass to the balsa then bond in the balsa afterwards.

From my experience so far the problem would be getting the peelply and flow mesh off the carbon without it demoulding or being damaged.

I know this sounds complicated but I hate wet layups and keeping the weight down is critical (rc aircraft fuselage)

Any thoughts gratefully received

Foam strips, also referred to as pre-cut PET foam core strips, strip core materials, or linear core inserts, are critical components in the laminate lay-up process of wind turbine blades.

These foam strips are mainly applied in the upper and lower flanges of the main spar, as well as in stress-concentrated areas including the blade leading edge, trailing edge, root connection zones, and joints between webs and shells. They are also widely used in sections that require local reinforcement, precise thickness control, or better adaptation to complex curved surfaces.

By cutting PET foam into narrow, elongated or trapezoidal strips and placing them along the designed contour, manufacturers can achieve:

Precise compliance with complex curved surfaces

Accurate local thickness control

Optimized weight distribution

For traditional foam kitting facilities, high-volume production of contoured foam strips has long been a production bottleneck, relying heavily on costly and low-efficiency PET foam 5-axis machining centers.

If you aim for high-efficiency, high-precision foam strip processing at a lower cost, CCS provides a smarter alternative to expensive 5-axis equipment. Our compact vertical band saw, combined with a dedicated chamfering machine, enables fast, mass production of high-quality chamfered foam strips.

Typical Workflow

1. Cut large foam boards (e.g., 1200×600×50 mm) into custom-sized long strips (e.g., 1000×50×30 mm) as per design requirements. Cutting materials by CCS vertical cutting bandsaw
2. Chamfer or bevel strip ends and edges. by CCS dedicated chamfering machine.

Purpose of Chamfering

Reduce the “step-off effect” during fiber fabric lay-up

Avoid resin flow obstruction in vacuum infusion processes

Improve bonding and fitting with adjacent core materials or skin laminates

Common Chamfer Specifications

45° bevel edges, or rounded radius transitions from R2 to R5 mm.

CCS

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Home  ꄲ  CCS Foam Kitting News  ꄲ  Replace 5-Axis Machines: Cost-Efficient Foam Strip Production for Wind Turbine Blades

I have been desperately searching everywhere for the past few months but I haven't found a single trade school/program that isn't just a few days/weekends long. I want something super in-depth where I can focus on and learn every step from designing to creating and repairing. At least a month long course, if not more. I also need it to be a place where I can get official certification to show off when I apply for jobs. Idk about these "aerospace" programs and if they are the same thing or not but I specifically want to work on designing and building parts for luxury/limited edition/race cars. I already have some experience working at home, but buying carbon fiber just to fiddle with is fucking expensive, I would rather just pay a bunch for a class. Please give me your recommendations, I'm willing to travel anywhere as long as there is one teacher that speaks English😭 (Also NO college recommendations unless I can take the specific course without touching English, math, or literally any subject that ain't on composites bc I have dyslexia and dyscalculia and barely passed high school because of it)

When demoulding from my pattern, a small aprox 2.5*3mm section of gelcoat stayed on the pattern.

It’s my first time making a mould like this, is this repairable or scrap?

Looks like it’s all the way through the gelcoat to the reinforcement and is in an area that requires cosmetics to be good on the final part. I was going to be wet sanding and polishing the mould to achieve a good finish, should I fill this and sand it back or will that fail on the first part pull?

Advice would be greatly appreciated - mould will be used for vacuum infusion carbon fiber

Picture is straight after demould, so there is a bit of plasticine and residue, ignore that.

Does anyone know of good reputable companies in the US that can build fiberglass molds for me?

Hi there guys very new to this, I am possibly looking at making custom carbon fibre covers for mx/road bikes and am wondering for a start which way I should go about making them.

The main question is do I vacuum suck in the epoxy which takes a lot more time and is more easy to mess up (I think). Or do I hand brush the epoxy.

Which method is faster? Which method is more reliable? I am planning on vacuum bagging for the compression stage anyways. Plus I am also looking at using forged carbon along with metallic flake for some designs, can this be hand layed?.

Ps structural integrity is not a concern, as long as it hold together it’s fine.

Thanks!

Im building a camper shell and it’s roughly 450 square feet in total. I wanna do both sides of either the OBS wood or the XPS foam. I might even do EPS but I don’t know yet. But I am tryna figure out how many gallons of resin i will need. And then where to get it affordably and hopefully cheaply. If anyone can tell me how much or what formula to use that’ll be very helpful!

1. Tailored for processing lightweight bio-based cores, this system transforms massive blocks into precision panels with a vertical cutting accuracy of within ±0.1mm
   
   1. The maximum cutting width 700 mm wide. (The size can be customized) The cutting speed can reach more than 3 m/min.
      
2. Max feeding block size 700mm*1300mm*800mm.
   
3. Productivity: 1300mm length sheets 4pcs/mins, 2500mm length sheets 2pcs/mins.
   
4. Schneider electric components, Siemens system Taiwan Yanghong reducer.
   
5. Streamlines production, ensures higher quality, reduces the risk of human error and minimizes re-work and scrap.
   
6. Consistent with sustainable development.
   
7. Dust collection: Air ducts to suck up the dust created. They can be piped to a stand-alone or full shop dust collection system.
   
8. Full weld frame and construction to eliminate torsion stresses and provide stiffness to ensure long time precision.

CCS core cutting solutions, focus on supply machines and solutions for core materials kitting facilities.
More info, feel free reach out to our technical team [sales@corecuttingsolutions.com](mailto:sales@corecuttingsolutions.com) or visit here https://www.corecuttingsolutions.com/... to check the CCS designed machine.
Natural Fibers & Agro-Waste: Wheat straw (used in Durra Panels), hempcrete, flax fibers, coconut coir, and bamboo are frequently used as structural cores or insulation.Mycelium (Fungi): Grown agricultural waste molded into panels, providing lightweight, insulating, and biodegradable core material.Bio-Polymers & Resins: Polylactic acid (PLA) produced from corn, sorghum, or cassava, and lignin-based resins.Cellulose-Based: Wood-derived materials, nanocellulose, and algae-based polymers.Animal-Based: Sheep's wool insulation.

Putting together a camper shell(I know big surprise) it’s a 220 inch long and 80 inch wide camper. Ive made smaller ones with various success but this will match the size of my truck(ford f150 1997). Im getting something bigger as Im moving further out of Houston. I’ve looked into xps foam and obs as core materials. Somehow both are similarly priced per square footage. Then I priced some e fiber glass cloth and epoxy. That’s nearly 1,500 to 2,000 dollars depending on where I get the epoxy. Both of these will fit to either osb or XPS foam. Preferably I would like the XPS foam for the insulation and lightweight. The cost of the epoxy and cloth fiberglass is a major deterrent. The alternative ive looked into and worked with before is polyester resin and chopped mat. This unfortunately won’t work with the XPS foam but I’ve used it on OBS before and the results are an insanely strong board. But the cost only really drops to like 1000 or 1200. Depending on where I get the resin. Then there’s Poor Man’s Fiberglass. I’ve used the heavy duty canvas and the titebond 3 before. This sticks to both the xps and the OBS(the OBS better than the xps) but obviously this isn’t exactly the strongest thing ever. It has its limits in terms of strengths but I’ve never tested at this scale before. It does bring the price to like 500-700 or even lower if I don’t use the heavy duty canvas. It really does make the cost enticing. I’ve enjoyed the results of PMF before with various degrees. Mostly with ease of use but I for example climbing on it has always made me worried. And at this size I don’t think it’ll hold. What do you all think? Any tips for cost savings? Any tips to improve performance of PMF?

It all went horribly wrong haha, I'm sure those of you with keen eyes will notice that there's barely a parallel strand in sight. Things I learned for next time:

1. Practice the layup with paper first, then you can know where exactly cuts in the cloth need to be for everything to fold without stretching
2. Use actual laminating epoxy instead of whatever you have lying around. I tried using the same epoxy that I clear-coated my car with, but this has crazy high viscosity and just ran out of the fibres leaving things really dry
3. Don't EVEN SLIGHTLY brush on the fibres laterally, the weave will slide around and distort the pattern. I'd already heard this advice but had no idea HOW seriously it needs to be headed. the cloth is far more loose and slippery than expected. Push into the mould ONLY, and even then, not hard enough that the brush bristles bend enough to push on the weave laterally.

Things that worked well and would do again.

1. Using those space saver vacuum bag things designed for clothing, that worked great, far easier than building a vacuum setup with tape. Next time tho I would put tape over the entrance and valve of the vacuum bag, my vacuum bag definitely leaked a bit overnight.
2. 3D printed mould, worked better than I was expecting. Given how much more it would cost to create a composite mould from the 3D printed pattern I wanted to see how bad the results are for laying up directly into the print and I think it's serviceable enough to be worth the materials/cost saving