steelheader Posted January 25, 2017 Report Share Posted January 25, 2017 I recently acquired a partially built 1/48th scale Pend Oreille kit of the PBM-5 Mariner. This kit was given to me at our local club meeting last night by a friend that felt he would not ever finish the build. The four-part fuselage has been assembled, the wings and pontoons are in place. My friend had planned to display the model in flight on a magnetic base so that he could change the display with the model level or banking as the mood might strike him. To achieve this flexibility he epoxied steel bars in the bottom of the hull. The bars are visible through the dorsal turret position. The bars are probably 1/8" thick, 1/2" wide and maybe 4" to 6" long. I can imagine that a large resin kit would be heavy enough on its own, but the added steel would further increase the weight. I can probably live with the steel in place if I must, but would like to remove it to make future handling during the rebuild process a bit easier. Also, I plan to install beaching gear, therefore the removal of the steel weights would reduce the stress on the gear. Does anyone have any thoughts on how I can loosen the hold the epoxy has on the steel? My first thought was to store the kit in our basement freezer for a day and then see if I can carefully pry the bars out. I recognize the freezing would probably make the resin more brittle, but my thinking is the steel may shrink and possibly separate from the epoxy. Remember, the bars are only accessible through the dorsal turret opening which is about 1" in diameter. Any help you may offer will be greatly appreciated. I was told this kit cost $200 several years ago, so it would be a shame not to make some effort to save and rebuild it. Link to comment Share on other sites More sharing options...
ghodges Posted January 25, 2017 Report Share Posted January 25, 2017 This sounds risky to me no matter how you try to remove those bars. Freezing might indeed cause the metal to shrink enough to "move" the epoxy, but it might STAY adhered to the epoxy and the shrinking then might rip cracks in your fiberglass bottom. Solvents would be risky too, as anything that would dissolve the bond might also dissolve the fiberglass. I think the easiest and safest approach is scratch build your beaching gear from metal. You can simply make it strong enough to support the weight instead of trying to remove the weight. That's how I'd approach it if it were mine. It IS an expensive, rare, and out of production kit to my knowledge, so cherish it accordingly! GIL :smiley16: Link to comment Share on other sites More sharing options...
WildBill50 Posted January 26, 2017 Report Share Posted January 26, 2017 I agree with Gil. Beaching gear isn't usually that complicated compared to regular gear. I may be wrong on this aircraft though. I would go that route though too. Too many variables to go wrong. Bill Link to comment Share on other sites More sharing options...
steelheader Posted January 26, 2017 Author Report Share Posted January 26, 2017 Thanks for the input. My wife already said I could not put my models in the freezer. Link to comment Share on other sites More sharing options...
Ron Bell Posted January 26, 2017 Report Share Posted January 26, 2017 I've checked around and the problem is that epoxy is a resin, but so if fiberglass! Anything you put on the epoxy could also effect the fiberglass theoretically. If the bars are too obvious through the windows, paint everything in there flat black. When the fuselage is closed up, not much light will get in and unless they go over the windows, they should be minimally visible. Only other solution I thought of was to go medieval on it and put a grinding tool in your Dremel and grind the epoxy away from the steel. Link to comment Share on other sites More sharing options...
dmorrissette Posted January 26, 2017 Report Share Posted January 26, 2017 Epoxy breaks down in sunlight. Fiberglass does not. If you aren't in a hurry, letting it sit in sunlight will eventually make the epoxy brittle but it will take time. Acetone would also do it but not sure the effect on that particular fiberglass. You could soak cotton balls in acetone and put against the epoxy carefully. It is also flammable too Dave Link to comment Share on other sites More sharing options...
steelheader Posted February 1, 2017 Author Report Share Posted February 1, 2017 Thanks to all for your comments. As I noted above the model is a partially assembled 1/48th scale resin kit. The steel weights are visible through the top turret and nose possible, and therefore access is quite restricted. After a Google search everything I found to remove or loosen epoxy is hazardous to one's health, flammable, smelly and generally not inviting. I have decided to live with the weights in place and begin the restoration and hopefully completion of the project. I expect this to be a very long-term activity. Go slow and plan the work. Thank you again. Link to comment Share on other sites More sharing options...
steelheader Posted February 21, 2017 Author Report Share Posted February 21, 2017 (edited) Here is an update on this project. We have had a spell of unseasonable warm weather for the last week, so I thought this would be a good time to go outside and remove the enamel paint previously applied by my friend. I used heavy-duty oven cleaner and water to rinse the paint and cleaner off the surface. It took two applications and most of the blue paint came off, but the white paint on the undersides appeared totally unfazed by all the attention. The second application did affect the epoxy holding the wing in place on the fuselage. I now have a separate wing section and fuselage to work on. Plus, I managed to break the struts on both wing floats. I also see that as a plus for future efforts. The steel bars at the bottom of the fuselage are now exposed, but I have decided to retain them in place and live with the extra weight. This should prove to be an interesting, if not challenging project. I will see about posting some images in the future for the progress. Edited February 21, 2017 by steelheader Link to comment Share on other sites More sharing options...
ghodges Posted February 22, 2017 Report Share Posted February 22, 2017 Looking forward to seeing your progress. Be sure to scrub away all of the oven cleaner in the corners to avoid future paint problems! GIL :smiley16: Link to comment Share on other sites More sharing options...
dmorrissette Posted February 22, 2017 Report Share Posted February 22, 2017 May be a pain but it will look really cool when you're done Dave Link to comment Share on other sites More sharing options...
steelheader Posted February 22, 2017 Author Report Share Posted February 22, 2017 I did give the model a good rinse with warm, soapy water after the oven cleaner exercise. An old toothbrush was used in all the nooks and crannies. Much more work to go to remove the paint and re-scribing the panel lines. Generally I wash the models with Dawn and warm water and a distilled water rinse prior to painting. At least two days of dry time follows the wash and rinse. Thanks for the pointers and support. More to come. Link to comment Share on other sites More sharing options...
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