# Filling in bubble on resin?



## FriesianFury (Dec 24, 2010)

I have resin that should be solid cast problem is most of it is but from one side of the belly and just a tad up to his should did not get filled with Resin mold (this is a horse model). So that part of the body is weak and breakable less I fill it in and then apoxie its out side afterwords. Problem is not sure what to use to fill it in?

I bought this horse off of the caster so I knew ahead of time the problem and worse case I will break the hole paper like area and rebuild it, just would like to try another way first before doing this.


Here is the hole and hallow part looking in the hole, its the top 4 photos
http://s746.photobucket.com/albums/xx107/friesianfurystudio/


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## GaryR (Feb 6, 2010)

I'll throw this out and you can see if you can use any of it. Method one; stick a small balloon through the sprue hole and blow it part way up. Brush on resin to patch. Method two; squirt a small bit of foam caulking in it and let it expand over night to see how much more is needed to fill it, being careful not to over fill it. Then patch the hole. 

My 2¢, hope this helps. 

GaryR


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## David Leech (Dec 9, 2008)

I think that I would approach it the other way around. 
Pour more casting resin into the horse, then use masking tape or scotch tape, to loosely cover the hole, but make sure that the perimeter is sealed, then turn the horse over and let it cure. 
You should get the hole filled so that it doesn't go flat across the hole, and the thin area thickened inside, so that you can then sand it smooth to make it all better! 
Of course, the trick will be to make sure that you pour enough in so that it will fill the hole and not get lost down the legs! 
Have a good Christmas, 
All the best, 
David Leech, Delta, Canada


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## Dansgscale (Jan 9, 2010)

I have to agree with David, get some resin and I highly recomend the TAP Plastic Quick Cast resin. This stuff is awesome. Two Part 50/50 mix and is as thin as water, cures in 20 minutes and can be sanded, drilled, milled, tapped and paints very well. I use it to cast up window and doors for my structures and I am working on a mold to cast the sides and ends for some D&RGW Stock Cars. The easy way to find out how much resin you need is to pour water into the Horse till it is full and then pour the water out into a measuring cup. That will tell you how many ounces of resin you will need. Then when you go to mix the resin use half that amount for each of part A and part B of the resin and you will have enough to fill the cavity up to the top. After filling the Horse , set it aside and let the resin cure and after it does, if there is a small dip or flat spot you can use "Squadran Green" White putty to smooth over the last bit. You should be able to get the Squadran Green putty at you local hobby shop. Some Michael's Craft stores also carry it. 

Dan S. 
Denver & Rio Grande Southern


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## cjwalas (Jan 2, 2008)

This looks like urethane resin? I would suggest carefully filling the holes with additional urethane resin in small, controllable batches. But don't even try to fill the area near the outer surface. I would use an epoxy sculpting putty (which usually adheres well to urethane) to do the finishing surface work with; you should be able to sculpt it fairly close to what you want and the finish sanding (if any) would be minimal. 
Chris


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## FriesianFury (Dec 24, 2010)

Thanks for all the tips and info on repairing him. I have this down in my studio and I am going to use it to fill it in. Just didnt want to less I knew it would be ok http://www.dickblick.com/products/smooth-on-smooth-cast-300/

I can up date you all on the filling with photos once done! Thanks again for all the help it was really helpful


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## David Leech (Dec 9, 2008)

Hi, 
Not sure if you have used this material before, but .... 
Smooth-Cast 300 will work just fine. 
As I said in an earlier thread here: 
http://www.mylargescale.com/Community/Forums/tabid/56/aff/8/aft/118408/afv/topic/Default.aspx 
MY method is to give the A + B a good shake and stir well before use. 
Let them sit for an hour or so, so any bubbles are released from the liquid. 
Then pour each mix into a clear (disposable) container so that you can see that there are no bubbles. 
Then gently mix them together well trying not to introduce to much air, but you must mix well. 
I do this for a count of 30 seconds, at which time I will pour. At this time, depending on the volume mixed, you WILL feel heat as the resin works on the principle of exotherm. 
Any bubbles WILL rise to the surface, so if you have the horse lying on its side with the hole taped over, then the bubbles (IF any) will rise to the inside of the horse and will not be seen. 
If you are filling up the whole horse to be solid, then of course you may get a couple of bubbles coming up to the surface. 
I am not sure if the exotherm will effect the cast horse. I wouldn't think so as it normally needs something like a hair dryer to soften cast urethane resin. 
If you still need to add some to fill the outside contours of the filled hole, you can always mix some more and brush it on. If you do, I would roughen the surface with some sandpaper so that the new resin can bite into the old, otherwise if you put it on a shiny resin surface, it will not 'stick' at all. 
Good luck, and let us know how it goes. 
All the best, 
David leech, Delta, Canada


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## Randy Stone (Jan 2, 2008)

I'm no expert for sure, but doesn't most resins get hot when kicking off? 

If so, the rest of the casting may warp. 

I would fill the void with paper or some other material so the patch, what ever you use, would be then and put off less heat when kicking off. 

Randy


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