Resin parts removal

those really arent that bad..... I wouldnt use ANY power tools thats for sure.... resin is really soft.....  I would get a sharp scalpel(pointed no 11 blade) and lightly trace around the edge gradually getting deeper.....    then when youve established a nice groove,  flip the blade... and pull the blade through using the opposite side as the leading edge.....this will remove more material than just parting it like the razor blade,,, again do this lightly....  dont force it,,,,,,, clean up the parts with a very sharp blade,,, the sand and polish.....

With resin parts its best to take your time......  I use either a blade.,... or really fine kerf modeler's saw.....  but nothing too aggresive.....     and remove small pieces of resin at a time.....  going to fast is the best way crack your part..,... 

Well, yes, it goes without saying that you should wear a dust mask, at least, when sanding or cutting resin.  So, no one said it

qmiester

I have a suggestion if I may - there are a lot of ideas here that obviously work and work well - however no one has mentioned safety.  You might consider A, if sanding, wet sand,  B. wearing a protective mask of one sort or another, C. performing the work in an operating airbrush booth or D. a combination of A , B and C.  The byproducts of cutting and sanding resins isn't exactly good on your lungs in the long run (This from someone who has a screaming in both ears earned from standing too close to large bore aircraft engines running at 52" of Manifold pressure, looking for leaks and loose objects and not wearing ear protection!) 

Ouch - hurts my ears just reading this!    Spent a lot of time around recips and jets (with ear plugs, tho).

Thanks, everyone, for all the good suggestions - I think I have it under control using several of the mentioned techniques.

Ken

I have a suggestion if I may - there are a lot of ideas here that obviously work and work well - however no one has mentioned safety.  You might consider A, if sanding, wet sand,  B. wearing a protective mask of one sort or another, C. performing the work in an operating airbrush booth or D. a combination of A , B and C.  The byproducts of cutting and sanding resins isn't exactly good on your lungs in the long run (This from someone who has a screaming in both ears earned from standing too close to large bore aircraft engines running at 52" of Manifold pressure, looking for leaks and loose objects and not wearing ear protection!) 

DoogsATX

I've got an old Dremel disc-belt sander that I use to chew through massive resin pour stubs. Have to be careful with it since it goes through resin fast, but I'd use it to thin those backing stubs down as thin as I dared, then move to a JLC saw to roughly cut out the parts and sand by hand from there. 

Doesn't look fun though...

That's a good point, and that's why I go with the sanding method.  It takes longer, but you have better control, less chance of slipping and damaging the piece.

I've got an old Dremel disc-belt sander that I use to chew through massive resin pour stubs. Have to be careful with it since it goes through resin fast, but I'd use it to thin those backing stubs down as thin as I dared, then move to a JLC saw to roughly cut out the parts and sand by hand from there. 

Doesn't look fun though...

Scorpiomikey

One way i found (I dont know if this is right, please berate me if im wrong) is i cut the part out roughly. then i laid a peice of wet/dry sandpaper (that was wet) on my cutting board and sanded it down till the excess flaked off.

I havent explained it very well. but hopefully that will help.

I'll second that, Mikey!

I had a set of 55 gallon drums in 1/72 for a diorama, they were cast with a large pour block that was about an 1/8 of an inch wider all around than the drums.  I used a piece of plate glass (salvaged from an old copier ), put the sandpaper on it, and sanded the piece down, till I could cut away the remaining little bits with a sharp X-Acto knife.

Ken, for your pieces, I would try using the sanding method for the intake scoop (is that what it is?) and for the longer, thin pieces, I would also try using a new Nr. 11 blade and scoring along their edges, undercutting them, as it were, until you can remove them from the pouring plug.

Hope that helps!

Brad

Thanks for responding, Hawk.  I've used thread on plastic, but never tried it on resin.  I'll check it out.

Ken

I  like to use thread.

OMCUSNR

I have a power scroll saw & a small belt/disc sander that would work well for stuff like that.  Another tool not to be without is a good Jeweler's saw.  Razor saws are often to stiff & bulky where a jeweler's coping saw can get in the fine places.

 

Reid

Thanks, Reid - I'll check out the jeweler's saw.

Ken

I have a power scroll saw & a small belt/disc sander that would work well for stuff like that.  Another tool not to be without is a good Jeweler's saw.  Razor saws are often to stiff & bulky where a jeweler's coping saw can get in the fine places.

Reid

Thanks, Don.  Yes, these really are EXTREME!  It took me most of an afternoon to cut out one of the canopy frames, (razor saw and sanding) and in the process it broke and I had to glue it back together.    These are from the C & H conversion kit to turn a F-102 into a TF-102.  Seems like a rather awful way to make them.  Don't have a bandsaw but think I will get out the Dremel and mask for the next attempt.  Actually, I might just scratch-build the thin ones from sheet styrene.  I think that would be a lot easier.  Thanks for your response.

By the way, very nicely written article in FSM.

Ken

The examples you showed seem to be extreme- I have never come across any that bad.  There is a real mix with resin casters, so  designing patterns and molds so that they don't look much different than die cast parts, others using extremely thick joins with sprues.

In some cases with small connections I merely use my sprue cutting pliers like I do with die cast styrene. In other cases with big gobs, I do resort to razor saws. I cut a bit away from the part and clean up with a dremel tool and sanding disk or sanding drum.

I have never had castings as bad as those shown, but if I did, I think I would resort to the bandsaw first, clean up a bit closer with razor saw, and then finish up with files or dremel/sander.

Thanks, guys.  Appreciate your responding.  I guess it will just take a lot of patience.

Ken

I would roughly cut out the parts and use 400grit wet/dry sandpaper laid on a true surface such as a piece of glass from a fairly small picture frame or mirror to gently sand them free.  It won't take all that long and, if done wet, dust won't be a problem.  Just don't get in a hurry and you'll be OK...

Good Luck

Ray

One way i found (I dont know if this is right, please berate me if im wrong) is i cut the part out roughly. then i laid a peice of wet/dry sandpaper (that was wet) on my cutting board and sanded it down till the excess flaked off.

I havent explained it very well. but hopefully that will help.

Wow. looks tough. You might have to use your dremel with a cut off wheel. If you have a variable speed one just turn it way down, and if you've used power tools before you shouldn't have any issues. Just dont get too close to the edge and plan on cleaning the parts up by sanding.