SEARCH FINESCALE.COM

Enter keywords or a search phrase below:

rtv mold

1913 views
6 replies
1 rating 2 rating 3 rating 4 rating 5 rating
  • Member since
    July 2014
rtv mold
Posted by detailer 1 on Sunday, November 30, 2014 7:43 PM

came up with a nice way to make a mold of a ho scale locomotive body.first mask the windows then fill the inside with rtv rubber up to the top and let it set.then flip it over and make a box with lego blocks and then pour the mold of the body.once set remove the blocks and take the master out and remove the rubber mold from the inside of the shell.then pour the resin in the mold and place the plug made with the rtv from the inside of shell,once resin sets take out resin shell and remove plug rtv rubber from inside.find it works better then a 2 piece.

  • Member since
    November 2014
Posted by BLACKSMITHN on Thursday, December 18, 2014 5:01 AM

Interesting! So, how'd it turn out? I'm considering making a mold to cast HO flat cars, as I have need for a great many. Have you ever done anything like that? I've never done any casting at all, so I'd appreciate any pointers.

  • Member since
    July 2014
Posted by detailer 1 on Thursday, December 18, 2014 2:34 PM

it turned out great have made 7 c630 bodies for cp rail units. only started casting this year tried many different brands the best I found were rubber mold was by chembar 2 part mixed by weight and the resin was from speciality resin both are found on ebay. found both items produced a great mold and resin casting. with the luck I have had with it not sure why I did not start along time ago.

  • Member since
    November 2014
Posted by BLACKSMITHN on Thursday, December 18, 2014 3:30 PM

Let me ask-- What level of detail can be achieved? Would it be possible, for instance, to mold a flat car side sill with stake pockets and not have the stake pockets turn out as solid lumps? I could do a flat sill without pockets and attach them individually, but that would be a royal pain considering how many are on each car.

  • Member since
    July 2014
Posted by detailer 1 on Thursday, December 18, 2014 6:24 PM

if you let the rtv fill in the holes on the master it should work out to make the pockets hallow might have a bit of flash.if you use the resin I said the detail is very great

  • Member since
    November 2014
Posted by BLACKSMITHN on Thursday, December 18, 2014 7:44 PM

That's great! Thanks for the info. I'm looking forward to starting work on a master! I can't wait to try this!

  • Member since
    November 2009
  • From: Twin Cities of Minnesota
Posted by Don Stauffer on Friday, December 19, 2014 10:18 AM

Some secrets to RTV molds for polyester resin are to have considerable height to mold to increase hydraulic pressure, and to use a J-shaped sprue shape to make resin enter mold cavity from bottom.  That way it doesn't fight air trying to escape cavity. Of course, you must have vent tubes from top of mold cavity, at least one at every local highspot.  The real secret of mold design is to think like an air bubble. If you were trapped in the mold cavity and wanted a way to get out, where would you like to see a vent tube?

Don Stauffer in Minnesota

JOIN OUR COMMUNITY!

Our community is FREE to join. To participate you must either login or register for an account.

SEARCH FORUMS
FREE NEWSLETTER
By signing up you may also receive reader surveys and occasional special offers. We do not sell, rent or trade our email lists. View our Privacy Policy.