vac infuz flanged molds ?

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#1

i am making an airbox that will be a 3 or 4 piece mold. because it is a complex shape i wanted to attempt infusion. Thinking about it, i have a concern that resin will be pulled through the flanges and lock my part to mold. The flanges i speak of are not just flanges arround the mold where you can tape your bag, but inter mold flanges holding the mold together. So i assume some type of selant is used on the intermold flanges?? is that the case and what is it? i dont think i would ever feel confident that i have sealed everything within. I wonder if silicone caulk would do it?

Thanks

#2

Any pictures?

I doubt you can VIP a 3d box, but do each one seperate and attach them together after molding each part.

#3

I assume this is going to be a carbon airbox. One thing to be careful of if your doing a several section mold infusion is that the parts line up exactly with no ridge or gaps no matter how small. When the mold is bolted together it must look like a one piece mold from inside. If not you will get an ugly line across the carbon where it has deformed slightly around the mold joins, this then rules out using any kind of flange sealant even if it did work. If possible you could still infuse the part but bag it, you would then have to protect the bag against the rough sides of the mold.

I have one mold that due to the flange i bag it and then infuse. I sanded all the rough glass and coated it with resin so no chance of bag punctures.

Baz

#4

Ok i have decided not to infuse this part. the interior is the smooth side so i am molding off a plug then using that mold to make an interior mold. Lots of molding, lots of flanging, lots of work. the interior dosent need to be perfect but i would rather have it be smooth inside than out.

this is not the finished plug as you can see some filler bumps. the indents are where latches mount


here is the location on the car, there will be an airbox top which goes from the roll hoop to the bottom half of the box. The top half box is not as crutial so i am ok with it having texture inside. Also the bottom half will have insulation on the outside. This is going to be a glass part made with high temp epoxy (lindoxy)

#5

what kind of car are you building…Id like to see some more pics of it.

As far as the airbox is concerned…Id infuse the sucker in pieces and just piece it together with 2" wide tape on the inside…

You dont want it to be glass smooth on the inside either…thats a myth. It wont help you in any kind of power or driveability as the inside should be relatively smooth just from using peelply.

I wouldnt go thru the headache of making and inner compression or sandwich mold for a part like that…its like re-inventing the wheel and I fear youll find it wasnt worth it.

#6

If the air-box is a one off, then mould it around a polystyrene plug, which is disolved with acetone when part is cured.

Better still make the box out of aluminuim, which is going to be far quicker than messing around with composites, and will need only cardboard patterns, a modicum of skill in forming metal, and a TIG welder.

#7

Order a gallon of Aquacore from http://www.acrtucson.com/index.htm. Make a very undersize plug core with some foam, and apply the Aquacore to the outside. Make the final shape, and wrap it with carbon/resin. When cured, rinse out the Aquacore with water and you’re done.

#8

guys. its no big deal, this is fun, i can mold from the outside or inside, my choice. I do think i will just use the peel ply texture on the inside and call this part quits a bit early. I decided to make the part out of composites rather than aluminum so that if anybody with the same car wants one i can make one and some $$. Also composite material is a far better insulator compared to aluminum, thirdly who wants to make this out of aluminum anyway. Another thing is that fiberglass will suit me just fine, assume this part to be two layers of 5.8 oz carbon, estimating the surface area to be 300in^2 this gives .167 Lb of cloth weight. Lets leave weight of resin out of this as it would be so similar between glass or carbon, now the same layup with glass at 6.0 oz is just 3.44% more weight ending in .173 Lb. Now again we have ignored the weight of resin and the different amount of required resin between the two, but we are talking about a pound here. I can live with having the inside of my (to be) insulated box be white instead of black.
I think I have updated my signature with a link to some pictures of the project but if not it is : http://s103.photobucket.com/albums/m132/r32sweet/AMAC%20RACECAR/

#9

ok so my profile is updated.

the car is a CROSSLE 65 formula ford 1.6 liter. weight class min is 1100 lbs wet with driver

#10

Remember that if you decide to use glass instead of carbon, it’s necessary to use either heavier fabric or more layers. 2 layers of 6oz glass is super flimsy!

#11

Do you have any links to that stuff? Ive been wanting to do a car project forever and would like to learn a little about that car stuff.

Ive heard of the formula ford…open wheel stuff right?

Would love any info you have on it…I think that stuff could be a ton of fun.

#12

Try www.scca.org or google SCCA. They even have autocrossing too USA wide.

#13

I agree that two layers is not much material and flimsy in some situations but this part has a lot of stiffness built in because it is small and changes direction frequently. Also when i say two layers i am referring to 0/90 and a 45 layup. The rear body section i built (signature link) was one layer of MAT and 2 layers of the same 6 oz cloth. Of course i needed to support the tail but that was expected, the rest of the body is perfectly stiff/light. I was very pleased with the stiffness of that layup and everybody considers MAT to not contribute much in general. Another factor for me is that that body was built with PER and i will be using some big $$ epoxy for this part.
I will know when it is done and if it needs reinforcement then i shall give it what it wants. For now i am going with the 2

#14

well Id like to see in depth stuff building the car…Ive been very interested.

#15

yea SCCA is the venue. I have attended Skip barber 3 day school but it was a few years ago and that experience doesn’t really count. So the process is to take a SCCA 2 day school and if you are competent enough, know the rules and play nice then you are on “probation”. Under probation you must participate in 2 races to upgrade your novice permit to a license and you are good to go from there. Of course you need a car or to rent one and to pay for everything but yes sir you can go race cars. this season will be my first and i have not passed school yet. I have been restoring that car to race for at least this season. You can check out www.APEXSPEED.com (racing forum) and see what’s going on.

#16

I also like (maybe I’ll start a racing series sticky thread in the motorsports section) www.grassrootsmotorsports.com too! Their magazine is awesome!

There is also http://www.nasaproracing.com/ too!

Or in So. Calif. area: www.touringcarclub.com